Cleaning method, method of manufacturing semiconductor device, substrate processing apparatus and non-transitory computer-readable recording medium

ABSTRACT

A cleaning method includes (a) providing a process chamber after forming an oxide film on a substrate in the process chamber formed by a reaction tube and a manifold supporting the reaction tube by performing a cycle a predetermined number of times, the cycle including supplying a source gas to the substrate through a first nozzle in the manifold extending upward to an inside of the reaction tube, and supplying an oxidizing gas to the substrate through a second nozzle in the manifold extending upward to the inside of the reaction tube; and (b) cleaning an inside of the process chamber. The step (b) includes a first cleaning process of supplying a hydrogen fluoride gas into the reaction tube through the second nozzle; and a second cleaning process of supplying a hydrogen fluoride gas onto an inner wall surface of the manifold through a third nozzle disposed in the manifold.

CROSS-REFERENCE TO RELATED PATENT APPLICATION

This U.S. non-provisional patent application claims priority under 35U.S.C. §119 of Japanese Patent Applications No. 2013-061907 and No.2014-039468 filed on Mar. 25, 2013 and Feb. 28, 2014, respectively, inthe Japanese Patent Office, the entire contents of which are herebyincorporated by reference.

BACKGROUND OF THE INVENTION

1. Field of the Invention

The present invention relates to a cleaning method, a method ofmanufacturing a semiconductor device, a substrate processing apparatusand a non-transitory computer-readable recording medium.

2. Description of the Related Art

As a method of cleaning an inside of a process chamber of a substrateprocessing apparatus, there is a cleaning method performed by supplyinga cleaning gas into a process chamber through a nozzle configured tosupply a processing gas for processing a substrate.

SUMMARY OF THE INVENTION

However, since a nozzle configured to supply a processing gas is oftendisposed so as to supply a gas toward a substrate, it is difficult toclean other portions, for example, the vicinity of an opening forunloading and unloading the substrate. Reaction by-products are likelyto remain in the portions in which cleaning is difficult. In order toremove the reaction by-products, a cleaning gas needs to be supplied fora long time or further cleaning needs to be performed manually by wipingand the like when cleaning using a gas is not sufficient. Thereby, thereis a problem in that a time required for cleaning increases.

An object of the present invention is to provide technology capable ofreducing a time required for cleaning.

According to an aspect of the present invention, there is provided acleaning method, including:

(a) providing a process chamber after forming an oxide film on asubstrate in the process chamber formed by a reaction tube and amanifold supporting the reaction tube by performing a cycle apredetermined number of times, the cycle including supplying a sourcegas to the substrate in the process chamber through a first nozzledisposed in the manifold and extending upward from the manifold to aninside of the reaction tube, and supplying an oxidizing gas to thesubstrate in the process chamber through a second nozzle disposed in themanifold and extending upward from the manifold to the inside of thereaction tube; and

(b) cleaning an inside of the process chamber,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

According to another aspect of the present invention, there is provideda method of manufacturing a semiconductor device, including:

(a) forming an oxide film on a substrate in the process chamber formedby a reaction tube and a manifold supporting the reaction tube byperforming a cycle a predetermined number of times, the cycle includingsupplying a source gas to the substrate in the process chamber through afirst nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube, and supplying an oxidizinggas to the substrate in the process chamber through a second nozzledisposed in the manifold and extending upward from the manifold to theinside of the reaction tube; and

(b) cleaning an inside of the process chamber after the step (a) isperformed,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

According to still another aspect of the present invention, there isprovided a substrate processing apparatus, including:

a process chamber formed by a reaction tube and a manifold supportingthe reaction tube;

a source gas supply system configured to supply a source gas into theprocess chamber;

an oxidizing gas supply system configured to supply an oxidizing gasinto the process chamber;

a hydrogen fluoride gas supply system configured to supply a hydrogenfluoride gas into the process chamber;

a first nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube;

a second nozzle disposed in the manifold and extending upward from themanifold to the inside of the reaction tube;

a third nozzle disposed in the manifold; and

a control unit configured to control the source gas supply system, theoxidizing gas supply system and the hydrogen fluoride gas supply systemto perform: (a) forming an oxide film on a substrate in the processchamber by performing a cycle a predetermined number of times, the cycleincluding supplying the source gas to the substrate in the processchamber through the first nozzle and supplying the oxidizing gas to thesubstrate in the process chamber through the second nozzle; and (b)cleaning an inside of the process chamber after performing the step (a),wherein the step (b) includes a first cleaning process of supplying thehydrogen fluoride gas into the reaction tube through the second nozzleand a second cleaning process of supplying the hydrogen fluoride gasonto an inner wall surface of the manifold through the third nozzle.

According to yet another aspect of the present invention, there isprovided a non-transitory computer-readable recording medium storing aprogram causing a computer to execute:

(a) forming an oxide film on a substrate in the process chamber formedby a reaction tube and a manifold supporting the reaction tube byperforming a cycle a predetermined number of times, the cycle includingsupplying a source gas to the substrate in the process chamber through afirst nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube, and supplying an oxidizinggas to the substrate in the process chamber through a second nozzledisposed in the manifold and extending upward from the manifold to theinside of the reaction tube; and

(b) cleaning an inside of the process chamber after the step (a) isperformed,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is a schematic configuration diagram illustrating a verticalprocessing furnace of a substrate processing apparatus preferably usedin an embodiment of the present invention and is a verticalcross-sectional view illustrating a processing furnace part.

FIG. 2 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 40 b in a first embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 3 is a schematic configuration diagram illustrating the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention and is a cross-sectional viewillustrating the processing furnace part taken along the line A-A ofFIG. 1.

FIG. 4 is a schematic configuration diagram illustrating a controller ofthe substrate processing apparatus preferably used in the embodiment ofthe present invention and is a block diagram illustrating a controlsystem of the controller.

FIG. 5 is a flowchart illustrating a substrate processing process of thepresent invention.

FIG. 6 is a diagram illustrating a timing of supplying a gas in afilm-forming sequence of the present invention.

FIG. 7 is a diagram illustrating a timing of supplying a cleaning gaswhen cleaning is performed.

FIGS. 8a and 8b are diagrams illustrating a cleaning method according toa temperature range in the vertical processing furnace of the substrateprocessing apparatus preferably used in the embodiment of the presentinvention.

FIG. 9 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 320 b in a second embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 10 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 330 b in a third embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 11 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 340 b in a fourth embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 12 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 350 b in a fifth embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 13 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 360 b in a sixth embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 14 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 40 b in a seventh embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

FIG. 15 is an enlarged partial cross-sectional view illustrating aperiphery of a nozzle 40 b in an eighth embodiment of the verticalprocessing furnace of the substrate processing apparatus preferably usedin the embodiment of the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS First Embodiment

The first embodiment of the present invention will be described.

(1) Configuration of Substrate Processing Apparatus

A processing furnace 12 includes a heater 14 serving as a heating unit(heating mechanism). The heater 14 has a cylindrical shape and isvertically installed by being supported by a heater base (notillustrated) serving as a holding plate. The heater 14 also functions asan activating mechanism (excitation unit) for activating a gas by heat.

In the heater 14, a reaction tube 16 is concentrically provided withrespect to the heater 14. The reaction tube 16 is formed to have acylindrical shape whose upper end is blocked and lower end is opened.The reaction tube 16 is made of a heat-resistant material such as quartz(SiO₂) and silicon carbide (SiC).

A manifold 18 (inlet flange) is concentrically provided with respect tothe reaction tube 16 below the reaction tube 16. The manifold 18 isformed to have a cylindrical shape whose upper end and lower end areopened and is made of a metal such as stainless. An upper end of themanifold 18 is engaged with a lower end of the reaction tube 16 and isconfigured to support the reaction tube 16.

An O ring 20 a is provided as a seal member between the manifold 18 andthe reaction tube 16. The manifold 18 is supported by the heater base,and thereby the reaction tube 16 is in a vertically installed state.

A process container (reaction container) mainly includes the reactiontube 16 and the manifold 18. A process chamber 22 is formed in acylindrical hollow portion of the process container. An opening forloading and unloading a wafer 24 as a substrate is formed below theprocess chamber 22. The process chamber 22 uses a boat 28 as a substrateholder for holding the wafer 24 to accommodate the wafer 24 in avertical arrangement of multiple stages in a horizontal posture.

The boat 28 holds a plurality of wafers 24 in multiple stages invertical and central alignment. The boat 28 is made of a heat-resistantmaterial such as quartz and SiC. An insulation member 30 made of aheat-resistant material such as quartz and SiC is provided in a bottomof the boat 28 and is configured such that heat from the heater 14 isnot easily delivered to a lower part. The insulation member 30 mayinclude a plurality of heat insulating plates made of a heat-resistantmaterial such as quartz and SiC and a heat insulating plate holder forhorizontally supporting these heat insulating plates in multiple stages.

The processing furnace 12 includes a first gas supply system 32configured to supply a first gas (for example, a source gas) forprocessing the wafer 24 into the process chamber 22, a second gas supplysystem 34 configured to supply a second gas (for example, a reactiongas) for processing the wafer 24 into the process chamber 22, and athird gas supply system 36 configured to supply a third gas (a cleaninggas) for cleaning an inside of the process chamber 22.

The processing furnace 12 includes three nozzles 40 a, 40 b, and 40 cfor introducing gases into the process chamber 22. These nozzles 40 a,40 b, and 40 c are provided so as to penetrate a sidewall of themanifold 18. The nozzles 40 a, 40 b, and 40 c are made of aheat-resistant material such as quartz and SiC. A gas supply pipe 42 aand an inert gas supply pipe 52 a are connected to the nozzle 40 a. Acleaning gas supply pipe 62 b and an inert gas supply pipe 52 b areconnected to the nozzle 40 b. A gas supply pipe 42 c, an inert gassupply pipe 52 c, a cleaning gas supply pipe 62 a, a gas supply pipe 42d, and an inert gas supply pipe 52 d are connected to the nozzle 40 c.

In this manner, the processing furnace 12 includes the three nozzles[the nozzles 40 a, 40 b, and 40 c], the three gas supply pipes [the gassupply pipes 42 a, 42 c, and 42 d], the four inert gas supply pipes [theinert gas supply pipes 52 a, 52 b, 52 c, and 52 d], and the two cleaninggas supply pipes [the cleaning gas supply pipes 62 a and 62 b]. Aplurality of types of gases are supplied into the process chamber 22.

(Source Gas Supply System: First Gas Supply System)

In the gas supply pipe 42 a, when a side of the process chamber 22 isset as a downstream side, in order from an upstream end, a mass flowcontroller (MFC) 44 a serving as a flow rate controller (flow ratecontrol unit) and a valve 46 a serving as an on-off valve are provided,and the inert gas supply pipe 52 a is connected to a downstream side ofthe valve 46 a. The nozzle 40 a is connected to a front end of the gassupply pipe 42 a. In order from an upstream end, an MFC 54 a and a valve56 a are provided in the inert gas supply pipe 52 a.

The nozzle 40 a is provided in a toric space between an inner wall ofthe reaction tube 16 and the wafer 24 accommodated in the processchamber 22, and is provided so as to extend upward in a stackingdirection of the wafer 24 from the manifold 18 to an inside of thereaction tube 16. The nozzle 40 a is provided so as to follow a regionthat is a side of a wafer arrangement region in which the wafer 24 isarranged and that horizontally surrounds the wafer arrangement region.The nozzle 40 a is configured as an L-shaped long nozzle. The nozzle 40a is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsupward from at least one end side of the wafer arrangement region towardthe other end side

A gas supply hole 48 a configured to supply a gas is provided in a sidesurface of the nozzle 40 a. The gas supply hole 48 a faces a center ofthe reaction tube 16 and is configured to supply a gas toward the wafer24 accommodated in the process chamber 22. A plurality of gas supplyholes 48 a are provided from a bottom to a top of the reaction tube 16at the same pitch, and each have the same opening area.

The first gas supply system 32 mainly includes the gas supply pipe 42 a,the MFC 44 a, and the valve 46 a. The nozzle 40 a also functions as apart of the first gas supply system 32. Also, an inert gas supply systemmainly includes the inert gas supply pipe 52 a, the MFC 54 a, and thevalve 56 a. The inert gas supply system also functions as a purge gassupply system.

A source gas containing a predetermined element and a halogen element issupplied from the gas supply pipe 42 a. As a source gas (a gascontaining Si and Cl) which contains silicon (Si) as the predeterminedelement and chlorine (Cl) as the halogen element, for example, ahexachlorodisilane (Si₂Cl₆, abbreviated to HCDS) gas, which is a kind ofchlorosilane-based source gas, is supplied from the gas supply pipe 42 ainto the process chamber 22 through the MFC 44 a, the valve 46 a, andthe nozzle 40 a. At this time, an inert gas may also be supplied fromthe inert gas supply pipe 52 a into the gas supply pipe 42 a through theMFC 54 a and the valve 56 a.

In the present embodiment, the first gas supply system 32 functions as asource gas supply system.

The chlorosilane-based source gas refers to a chlorosilane-basedmaterial in a gas state, for example, a gas obtained by vaporizing achlorosilane-based material that is in a liquid state under normaltemperature and normal pressure, or a chlorosilane-based material thatis in a gas state under normal temperature and normal pressure. Inaddition, the chlorosilane-based material refers to a silane-basedmaterial having a chloro group as a halogen group and refers to a sourcecontaining at least Si and Cl. The chlorosilane-based material referredto herein may be a kind of halide.

In this specification, the term “source” may refer to either or both of“a liquid source in a liquid state” and “a source gas in a gas state.”In this specification, the term “chlorosilane-based material” may referto either or both of “a chlorosilane-based material in a liquid state”and “a chlorosilane-based source gas in a gas state.” When a liquidsource that is in a liquid state under normal temperature and normalpressure such as HCDS is used, the liquid source is vaporized by avaporization system such as a vaporizer and a bubbler and is supplied asa source gas (HCDS gas).

(Reaction Gas Supply System: Second Gas Supply System)

In the gas supply pipe 42 c, in order from an upstream end, an MFC 44 cand a valve 46 c are provided, and the inert gas supply pipe 52 c isconnected downstream from the valve 46 c. In the inert gas supply pipe52 c, in order from an upstream end, an MFC 54 c and a valve 56 c areprovided. The nozzle 40 c is connected to a front end of the gas supplypipe 42 c.

The nozzle 40 c is provided so as to extend upward in a stackingdirection of the wafer 24 from a bottom to a top of the inner wall ofthe reaction tube 16. The nozzle 40 c is provided so as to follow aregion that is a side of a wafer arrangement region in which the wafer24 is arranged and that horizontally surrounds the wafer arrangementregion. The nozzle 40 c is configured as an L-shaped long nozzle. Thenozzle 40 c is provided such that a horizontal portion thereofpenetrates a sidewall of the manifold 18 and a vertical portion thereofextends upward from at least one end side of the wafer arrangementregion toward the other end side.

A gas supply hole 48 c configured to supply a gas is provided in a sidesurface of the nozzle 40 c. The gas supply hole 48 c faces a center ofthe reaction tube 16 and is configured to supply a gas toward the wafer24 accommodated in the process chamber 22.

A plurality of gas supply holes 48 c are provided from a bottom to a topof the reaction tube 16.

The gas supply pipe 42 d is connected downstream from the valve 46 c ofthe gas supply pipe 42 c and the valve 56 c of the inert gas supply pipe52 c. In the gas supply pipe 42 d, in order from an upstream end, an MFC44 d and a valve 46 d are provided, and the inert gas supply pipe 52 dis connected downstream from the valve 46 d. In the inert gas supplypipe 52 d, in order from an upstream end, an MFC 54 d and a valve 56 dare provided.

The second gas supply system 34 mainly includes the nozzle 40 c, the gassupply pipes 42 c and 42 d, the MFCs 44 c and 44 d, and the valves 46 cand 46 d. The inert gas supply system mainly includes the inert gassupply pipes 52 c and 52 d, the MFCs 54 c and 54 d, and the valves 56 cand 56 d. The inert gas supply system also functions as a purge gassupply system.

A gas (oxygen-containing gas) which contains oxygen, that is anoxidizing gas (oxidation gas), is supplied from the gas supply pipe 42 cas a reaction gas. As an oxygen-containing gas, for example, oxygen (O₂)gas is supplied into the process chamber 22 through the MFC 44 c, thevalve 46 c, the gas supply pipe 42 c, and the nozzle 40 c. At this time,the inert gas may also be supplied from the inert gas supply pipe 52 cinto the gas supply pipe 42 c through the MFC 54 c and the valve 56 c.

A gas (hydrogen-containing gas) which contains hydrogen, that is areducing gas (reduction gas), is supplied from the gas supply pipe 42 das a reaction gas. As a hydrogen-containing gas, for example, hydrogen(H₂) gas is supplied into the process chamber 22 through the MFC 44 d,the valve 46 d, the gas supply pipe 42 d, and the nozzle 40 c. At thistime, an inert gas may also be supplied from the inert gas supply pipe52 d into the gas supply pipe 42 d through the MFC 54 d and the valve 56d.

In the present embodiment, the second gas supply system 34 functions asa reaction gas supply system.

(Cleaning Gas Supply System: Third Gas Supply System)

The cleaning gas supply pipe 62 a is connected to the gas supply pipe 42c. In the cleaning gas supply pipe 62 a, in order from an upstream end,an MFC 64 a and a valve 66 a are provided. The nozzle 40 c is connectedto a front end of the cleaning gas supply pipe 62 a through the gassupply pipe 42 c. In the cleaning gas supply pipe 62 b, in order from anupstream end, an MFC 64 b and a valve 66 b are provided, and the inertgas supply pipe 52 b is connected downstream from the valve 66 b. In theinert gas supply pipe 52 b, in order from an upstream end, an MFC 54 band a valve 56 b are provided. The nozzle 40 b is connected to a frontend of the cleaning gas supply pipe 62 b. The nozzle 40 b is disposed soas to face an exhaust pipe 90 (described later) with the boat 28accommodated in a process chamber 20, that is, the wafer 24, interposedtherebetween as seen in a plan view (refer to FIG. 3). Also, in FIG. 1,positions of the nozzles 40 a, 40 b, and 40 c, the exhaust pipe 90, andthe like are conveniently shown for illustration.

The nozzle 40 b is configured as an L-shaped short nozzle. The nozzle 40b is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsupward along an inner wall of the manifold 18.

A gas supply hole 48 b configured to supply a gas is provided in aleading end of the nozzle 40 b, and the gas supply hole 48 b is openedupward [opened in a direction from the manifold 18 side toward thereaction tube 16 side]. The nozzle 40 b is configured to supply a gas tothe manifold 18 side relative to a position in which the nozzle 40 asupplies a gas. In addition, the nozzle 40 b is able to supply a gastoward an inner wall surface of the manifold 18.

A first cleaning gas supply system mainly includes the nozzle 40 c, thecleaning gas supply pipe 62 a, the MFC 64 a, and the valve 66 a. Inaddition, a second cleaning gas supply system mainly includes the nozzle40 b, the cleaning gas supply pipe 62 b, the MFC 64 b, and the valve 66b. Also, the inert gas supply system includes the inert gas supply pipe52 b, the MFC 54 b, and the valve 56 b. The inert gas supply system alsofunctions as a purge gas supply system. The third gas supply system 36is a cleaning gas supply system that includes the first cleaning gassupply system and the second cleaning gas supply system.

In the present embodiment, a cleaning gas is supplied from the cleaninggas supply pipe 62 a. As the cleaning gas, for example, hydrogenfluoride (HF) gas is supplied as a gas containing fluorine(fluorine-containing gas) from the cleaning gas supply pipe 62 a intothe process chamber 22 [mainly to the inner wall of the reaction tube16] through the MFC 64 a, the valve 66 a, the gas supply pipe 42 c, andthe nozzle 40 c. At this time, the inert gas may also be supplied fromthe inert gas supply pipes 52 c and 52 d into the process chamber 22through the MFCs 54 c and 54 d, the valves 56 c and 56 d, the gas supplypipe 42 c, and the nozzle 40 c.

Similarly, the cleaning gas is supplied from the cleaning gas supplypipe 62 b. As the cleaning gas, for example, hydrogen fluoride (HF) gasis supplied as a gas containing fluorine (fluorine-containing gas) fromthe cleaning gas supply pipe 62 b into the process chamber 22 [mainly toan inner wall of the manifold 18] through the MFC 64 b, the valve 66 b,and the nozzle 40 b. At this time, the inert gas may also be suppliedfrom the inert gas supply pipe 52 b into the cleaning gas supply pipe 62b through the MFC 54 b and the valve 56 b.

In the present embodiment, the third gas supply system 36 functions as acleaning gas supply system.

In the present embodiment, a gas is transferred through the nozzle 40 aand the nozzle 40 c which are disposed in a toric longitudinal spaceformed by the inner wall of the reaction tube 16 and ends of a pluralityof stacked wafers 24, that is, a cylindrical-shaped space. Through thegas supply hole 48 a and the gas supply hole 48 c, a gas is suppliedinto the reaction tube 16 in the vicinity of the wafer 24. A gas flow inthe reaction tube 16 is mainly in a direction (horizontal direction)parallel to a surface of the wafer 24. Thereby, a gas is uniformlysupplied to each of the wafers 24 accommodated in the process chamber 22and a thin film having a uniform film thickness is formed on the wafer24. A gas (a residual gas after reaction) flowing over a surface of thewafer 24 flows in a direction of the exhaust pipe 90. The direction inwhich the residual gas flows is not limited to a vertical direction butmay be appropriately set according to a position of an exhaust port.

(Exhaust System)

In the reaction tube 16, the exhaust pipe 90 configured to exhaust anatmosphere in the process chamber 22 is provided. In the exhaust pipe90, a vacuum pump 96 is connected as a vacuum exhaust device through apressure sensor 92 configured to detect a pressure in the processchamber 22 as a pressure detector (pressure detecting unit) and an autopressure controller (APC) valve 94 serving as a pressure regulator(pressure regulating unit). While the vacuum pump 96 is operated,vacuum-exhaust or vacuum-exhaust stop in the process chamber 22 isperformed by opening or closing the APC valve 94. In addition, while thevacuum pump 96 is operated, a pressure in the process chamber 22 isadjusted by regulating a degree of valve opening of the APC valve.

An exhaust system mainly includes the exhaust pipe 90, the pressuresensor 92, and the APC valve 94. The vacuum pump 96 may also be includedin the exhaust system. While the vacuum pump 96 is operated, the exhaustsystem regulates a degree of opening of the APC valve 94 based oninformation on the pressure detected by the pressure sensor 92, andthereby vacuum-exhausts such that the pressure in the process chamber 22becomes a predetermined pressure (degree of vacuum). The exhaust pipe 90is not limited to being provided in the reaction tube 16 but may also beprovided in the manifold 18 similar to the nozzle 40 a or the nozzle 40b.

(Opening and Closing Mechanism and Raising and Lowering Mechanism)

As a first furnace port cover, a seal cap 100 configured to hermiticallyclose a lower-end opening of the manifold 18 is provided below themanifold 18. The seal cap 100 is configured to abut a lower end of themanifold 18 from a bottom side in a vertical direction. The seal cap 100is made of a metal such as stainless and is formed in a disk shape. In atop surface of the seal cap 100, as a seal member, an O ring 20 babutting the lower end of the manifold 18 is provided.

In a side (a bottom side in FIG. 1) opposite to the process chamber 22of the seal cap 100, a rotating mechanism 102 configured to rotate theboat 28 is provided. A rotary shaft 104 of the rotating mechanism 102 ismade of a metal such as stainless and is connected to the boat 28 bypenetrating the seal cap 100. The rotating mechanism 102 rotates thewafer 24 held on the boat 28 by rotating the boat 28.

A boat elevator 106 as a raising and lowering mechanism is verticallyprovided outside the reaction tube 16. The boat elevator 106 isconfigured to raise and lower the seal cap 100 in a vertical direction.The boat elevator 106 loads or unloads the boat 28 mounted on the sealcap 100 into or from the process chamber 22 by raising or lowering theseal cap 100. The boat elevator 106 functions as a transfer device(transfer mechanism) configured to transfer the boat 28 [and the wafer24 held thereon] inside or outside the process chamber 22.

As a second furnace port cover, a shutter 110 configured to hermeticallyclose a lower-end opening of the manifold 18 is provided below themanifold 18. The shutter 110 is formed in a disk shape and is made of ametal such as stainless. In a top surface of the shutter 110, as a sealmember, an O ring 20 c abutting the lower end of the manifold 18 isprovided. The shutter 110 closes the lower-end opening when the seal cap100 moves down and the lower-end opening of the manifold 18 is opened,and is retracted from the lower-end opening when the seal cap 100 movesup and the lower-end opening of the manifold 18 is closed. The shutter110 is controlled such that an opening and closing operation (such as araising and lowering operation and a rotational operation) is performedby a shutter opening and closing mechanism 112 provided outside thereaction tube 16.

In the reaction tube 16, a temperature sensor 114 serving as atemperature detector is provided (refer to FIG. 3). Power supply to theheater 14 is adjusted based on information on the temperature detectedby the temperature sensor 114, and thereby a temperature in the processchamber 22 has a desired temperature distribution. The temperaturesensor 114 is configured as an L-shape similar to the nozzle 40 a andthe nozzle 40 c and is provided along the inner wall of the reactiontube 16.

A controller 200 serving as a control unit (control device) isconfigured as a computer which includes a central processing unit (CPU)202, a random access memory (RAM) 204, a memory device 206, and an I/Oport 208. The RAM 204, the memory device 206 and the I/O port 208 areconfigured to exchange data with the CPU 202 through an internal bus210. An I/O device 212 such as a touch panel is connected to thecontroller 200.

The memory device 206 includes, for example, a flash memory and a harddisk drive (HDD). A control program controlling operations of asubstrate processing apparatus 10, a process recipe describingsequences, conditions, and the like of substrate processing(film-forming process) (described later), a cleaning recipe describingsequences, conditions, and the like of a cleaning process (describedlater), and the like are readably stored in the memory device 206.

The process recipe, which is a combination of sequences, causes thecontroller 200 to execute each sequence in a substrate processingprocess in order to obtain a predetermined result, and functions as aprogram. Also, the cleaning recipe, which is a combination of sequences,causes the controller 200 to execute each sequence in a cleaning process(described later) in order to obtain a predetermined result, andfunctions as a program. Hereinafter, the process recipe, the cleaningrecipe, the control program, and the like are collectively simply calleda “program.” In this specification, the term “program” may refer to onlythe process recipe, only the cleaning recipe, or only the controlprogram, and any combination of the process recipe, the cleaning recipeand the control program.

The RAM 204 is configured as a memory area (work area) in which aprogram, data, and the like read by the CPU 202 are temporarily stored.

The I/O port 208 is connected to the MFCs 44 a, 44 c, 44 d, 54 a, 54 b,54 c, 54 d, 64 a, and 64 b, the valves 46 a, 46 c, 46 d, 56 a, 56 b, 56c, 56 d, 66 a, and 66 b, the pressure sensor 92, the APC valve 94, thevacuum pump 96, the heater 14, the temperature sensor 114, the rotatingmechanism 102, the boat elevator 106, the shutter opening and closingmechanism 112, and the like.

The CPU 202 reads and executes the control program from the memorydevice 206, and reads the process recipe or the cleaning recipe from thememory device 206 according to an input of a manipulating command fromthe I/O device 212 and the like. To comply with content of the readprocess recipe or cleaning recipe, the CPU 202 is configured to controla flow rate adjustment operation of various types of gases by the MFCs44 a, 44 c, 44 d, 54 a, 54 b, 54 c, 54 d, 64 a, and 64 b, an opening andclosing operation of the valves 46 a, 46 c, 46 d, 56 a, 56 b, 56 c, 56d, 66 a, and 66 b, a pressure adjustment operation by the APC valve 94based on an opening and closing operation of the APC valve 94 and thepressure sensor 92, starting and stopping of the vacuum pump 96, arotation and rotational speed regulating operation of the boat 28 by therotating mechanism 102, a raising and lowering operation of the boat 28by the boat elevator 106, an opening and closing operation of theshutter 110 by the shutter opening and closing mechanism 112, and thelike.

The controller 200 is not limited to being configured as a dedicatedcomputer but may be configured as a general-purpose computer. Forexample, an external memory device 220 storing the program is prepared,the program is installed in the general-purpose computer using theexternal memory device 220, and thereby the controller 200 according tothe present embodiment may also be configured. Examples of the externalmemory device 220 may include a magnetic tape, a magnetic disk such as aflexible disk and a hard disk, an optical disc such as a CD and a DVD, amagneto-optical disc such as an MO, and a semiconductor memory such as aUSB memory and a memory card.

A device for providing the program to the computer is not limited to theexternal memory device 220 for providing the program. For example, theprogram may also be provided using a communication unit such as theInternet or a dedicated line without the external memory device 220.

The memory device 206 or the external memory device 220 is configured asa non-transitory computer-readable recording medium. Hereinafter, theseare also collectively simply called a recording medium. When the term“recording medium” is used in this specification, it refers to either orboth of the memory device 206 and the external memory device 220.

(2) Substrate Processing Process

Next, as a process of a manufacturing process of a semiconductor deviceusing the processing furnace 12 of the substrate processing apparatus10, a method in which a process of forming a thin film on the wafer 24as a substrate is performed, and then cleaning the inside of the processchamber 22 is performed will be described. Operations of respectiveunits constituting the substrate processing apparatus 10 are controlledby the controller 200.

When the term “wafer” is used in this specification, it refers to the“wafer itself,” or a “laminate (aggregate) of a wafer, a predeterminedlayer, film, and the like formed on a surface thereof” (that is, thewafer refers to a wafer including a predetermined layer, film, and thelike formed on a surface thereof). In addition, when the term “surfaceof the wafer” is used in this specification, it refers to a “surface(exposed surface) of the wafer itself” or a “surface of a predeterminedlayer, film, and the like formed on the wafer, that is, the outermostsurface of the wafer as the laminate.”

Therefore, when it is described in this specification that “apredetermined gas is supplied to the wafer,” it means that “apredetermined gas is directly supplied to a surface (exposed surface) ofwafer itself” or “a predetermined gas is supplied to a layer, film, andthe like formed on the wafer, that is, to the outermost surface of thewafer as the laminate.” In addition, when it is described in thisspecification that “a predetermined layer (or film) is formed on thewafer,” it means that “a predetermined layer (or film) is directlyformed on a surface (exposed surface) of wafer itself” or “apredetermined layer (or film) is formed on a layer, film, and the likeformed on the wafer, that is, form a predetermined layer (or film) onthe outermost surface of the wafer as the laminate.”

The terms “substrate” and “wafer” as used in this specification have thesame meanings. Thus, the term “wafer” in the above description may bereplaced with the term “substrate.”

Hereinafter, an example in which a silicon oxide film (SiO₂ film,hereinafter also referred to as a “SiO film”) is formed on the wafer 24using HCDS gas as a source gas and O₂ gas and H₂ gas as a reaction gas,and then the inside of the process chamber 22 is cleaned using HF gas asa cleaning gas will be described with reference to FIGS. 5, 6, and 7.

<Wafer Charging and Boat Loading>

First, a plurality of wafers 24 are loaded on the boat 28 (wafercharging). When the wafers 24 are loaded on the boat 28, the shutter 110is moved by the shutter opening and closing mechanism 112, and therebythe lower-end opening of the manifold 18 is opened (shutter opening).The boat 28 on which the plurality of wafers 24 are held is lifted bythe boat elevator 106 and is loaded (boat loading) in the processchamber 22. The seal cap 100 seals the lower end of the manifold 18through the O ring 20 b.

<Pressure Adjustment and Temperature Adjustment>

Subsequently, the inside of the process chamber 22 is vacuum-exhaustedto a desired pressure (degree of vacuum) by the vacuum pump 96. At thistime, the pressure in the process chamber 22 is measured by the pressuresensor 92, and the APC valve 94 is feedback-controlled (pressureadjustment) based on information on the measured pressure. The vacuumpump 96 constantly operates while at least processing on the wafer 24 iscompleted.

The inside of the process chamber 22 is heated to a desired temperatureby the heater 14. At this time, based on information on the temperaturedetected by the temperature sensor 114, power supply to the heater 14 isfeedback-controlled (temperature adjustment) such that the inside of theprocess chamber 22 has a desired temperature distribution. Heating theinside of the process chamber 22 by the heater 14 is continuouslypreformed while at least processing on the wafer 24 is completed.

Subsequently, the boat 28 and the wafer 24 are rotated by the rotatingmechanism 102. Rotation of the boat 28 and the wafer 24 by the rotatingmechanism 102 is continuously preformed while at least processing on thewafer 24 is completed.

<Process of Forming Silicon Oxide Film>

Then, as illustrated in FIGS. 5 and 6, a SiO film having a predeterminedfilm thickness is formed on the wafer 24 by performing a cycle includingthe following steps 1 to 4 a predetermined number of times.

(Step 1)

In step 1, a source gas (HCDS gas) is supplied to the wafer 24accommodated in the process chamber 20 and a layer (silicon-containinglayer) is formed on the wafer 24.

First, the valve 46 a of the gas supply pipe 42 a is opened, and theHCDS gas flows into the gas supply pipe 42 a. The HCDS gas flows fromthe gas supply pipe 42 a and a flow rate thereof is adjusted by the MFC44 a. The HCDS having the adjusted flow rate is supplied from the gassupply hole 48 a of the nozzle 40 a toward the wafer 24 in the processchamber 22 in a heated and depressurized state and is exhausted from theexhaust pipe 90. In this manner, the HCDS gas is supplied to the wafer24 (HCDS gas supply).

At this time, the valve 56 a of the inert gas supply pipe 52 a isopened, and N₂ gas may also be supplied as an inert gas from the inertgas supply pipe 52 a. A flow rate of the N₂ gas is adjusted by the MFC54 a and the N₂ gas is supplied into the gas supply pipe 42 a. The N₂gas having the adjusted flow rate and the HCDS gas having the adjustedflow rate are mixed in the gas supply pipe 42 a, are supplied from thegas supply hole 48 a of the nozzle 40 a into the process chamber 22 in aheated and depressurized state, and are exhausted from the exhaust pipe90.

In order to prevent the HCDS gas from being introduced into the nozzles40 b and 40 c, the valves 56 b, 56 c, and 56 d are opened, and the N₂gas flows into the inert gas supply pipes 52 b, 52 c, and 52 d. The N₂gas is supplied into the process chamber 22 through the cleaning gassupply pipe 62 b, the gas supply pipe 42 c, the gas supply pipe 42 d,the nozzle 40 b and the nozzle 40 c, and is exhausted from the exhaustpipe 90.

At this time, the APC valve 94 is adjusted such that the pressure in theprocess chamber 22 falls within, for example, a range of 1 Pa to 13,300Pa, and preferably 10 Pa to 1,330 Pa. A supply flow rate of the HCDS gascontrolled by the MFC 44 a is set to have a flow rate of, for example, arange of 1 sccm to 1,000 sccm. A supply flow rate of the N₂ gascontrolled by the MFCs 54 a, 54 b, 54 c, and 54 d is set to fall within,for example, a range of 100 sccm to 2,000 sccm. A time for supplying theHCDS gas to the wafer 24, that is, a gas supply time (radiation time),is set to fall within, for example, the range of 1 second to 120seconds.

The temperature of the heater 14 is set such that the temperature of thewafer 24 falls within, for example, a range of 350° C. to 800° C.,preferably 450° C. to 800° C., and more preferably 550° C. to 750° C.

When the temperature of the wafer 24 is less than 350° C., the HCDS ishardly decomposed and adsorbed on the wafer 24, and thereby a practicalfilm-forming rate may not be obtained. When the temperature of the wafer24 is set to 350° C. or more, this problem is addressed and thereby asufficient film-forming rate may be obtained. When the temperature ofthe wafer 24 is set to 450° C. or more, an effect of oxidizing powerimprovement is significant in step 3 (described later). When thetemperature of the wafer 24 is set to 550° C. or more, the HCDS issufficiently decomposed.

When the temperature of the wafer 24 is set to 750° C., andparticularly, more than 800° C., a CVD reaction becomes strong [agas-phase reaction is dominant] so that film thickness uniformity islikely to be degraded and thereby control thereof may be difficult. Whenthe temperature of the wafer 24 is set to 800° C. or less, degradationof the film thickness uniformity is suppressed and thereby controlthereof becomes easier. In particular, when the temperature of the wafer24 is set to 750° C. or less, the film thickness uniformity is easilysecured and thereby control thereof becomes easy.

Under the above-described conditions, when the HCDS gas is supplied tothe wafer 24, a silicon-containing layer (Si-containing layer) having athickness of, for example, about less than one atomic layer to severalatomic layers is formed on the wafer 24 [an underlying film of asurface]. The Si-containing layer may include either or both of asilicon layer (Si layer) and an adsorption layer of the HCDS gas.Preferably, the Si-containing layer is a layer containing silicon (Si)and chlorine (Cl).

The Si layer generically refers to a continuous layer formed of Si, adiscontinuous layer, or a Si thin film formed by overlapping theselayers. The continuous layer formed of Si may also be called a Si thinfilm. Si forming the Si layer also includes Si in which a bond with Clis not completely disconnected.

The adsorption layer of the HCDS gas includes a chemical adsorptionlayer in which gas molecules of the HCDS gas are continuous and achemical adsorption layer in which gas molecules of the HCDS gas arediscontinuous. That is, the adsorption layer of the HCDS gas includes achemical adsorption layer that is formed of the HCDS molecules and has athickness of one molecule layer or less than one molecule layer. TheHCDS (Si₂Cl₆) molecules forming the adsorption layer of the HCDS gasalso include molecules in which a bond between Si and Cl is partiallydisconnected.

“Layer having a thickness of less than one atomic layer” refers to adiscontinuously formed atomic layer. “Layer having a thickness of oneatomic layer” refers to a continuously formed atomic layer. “Layerhaving a thickness of less than one molecule layer” refers to adiscontinuously formed molecule layer. “Layer having a thickness of onemolecule layer” refers to a continuously formed molecule layer.

Under conditions in which the HCDS gas is self-decomposed (pyrolyzed),that is, conditions causing a pyrolysis reaction of the HCDS, when Si isdeposited on the wafer 24, the Si layer is formed. Under conditions inwhich the HCDS gas is not self-decomposed (pyrolyzed), that is,conditions that do not cause a pyrolysis reaction of the HCDS, when theHCDS gas is adsorbed on the wafer 24, the adsorption layer of the HCDSgas is formed. Forming the Si layer on the wafer 24 is preferable sincea film-forming rate is higher when the Si layer is formed on the wafer24 than when the adsorption layer of the HCDS gas is formed on the wafer24,

When the thickness of the Si-containing layer formed on the wafer 24 ismore than several atomic layers, an oxidation (modification) action instep 3 does not influence on the entire Si-containing layer. Also, aminimum thickness of the Si-containing layer that can be formed on thewafer 24 is less than one atomic layer. Therefore, preferably, theSi-containing layer may be set to have a thickness of less than oneatomic layer to several atomic layers.

When the thickness of the Si-containing layer is set to one atomic layeror less, that is, one atomic layer or less than one atomic layer, anaction of an oxidation reaction (modifying reaction) in step 3relatively increases, and a time required for the oxidation reaction instep 3 decreases. Also, a time required for forming the Si-containinglayer in step 1 decreases. Thereby, a processing time required forperforming one cycle decreases, and a processing time in totaldecreases. That is, the film-forming rate increases. In addition, whenthe thickness of the Si-containing layer is set to one atomic layer orless, controllability of the film thickness uniformity increases.

The HCDS gas supplied into the process chamber 22 is supplied to thewafer 24 and is also supplied to a surface of a member in the processchamber 22 [a surface of a member such as the inner wall of the reactiontube 16, the inner wall of the manifold 18, and the boat 28 provided inthe process chamber 22]. Thereby, the Si-containing layer is formed onthe wafer 24 and is also formed on the surface of the member in theprocess chamber 22. The Si-containing layer formed on the surface of themember in the process chamber 22 may also include either or both of asilicon layer (Si layer) and an adsorption layer of the HCDS gas as inthe Si-containing layer formed on the wafer 24.

As the source gas (a gas containing silicon and chlorine), instead ofthe HCDS gas, tetrachlorosilane (silicon tetrachloride, SiCl₄,abbreviated to STC) gas, trichlorosilane (SiHCl₃, abbreviated to TCS)gas, dichlorosilane (SiH₂Cl₂, abbreviated to DCS) gas, andmonochlorosilane (SiH₃Cl, abbreviated to MCS) gas may also be used. Asthe inert gas, instead of the N₂ gas, a rare gas such as argon (Ar),helium (He), neon (Ne), and xenon (Xe) may also be used.

(Step 2)

After the Si-containing layer is formed on the wafer 24, the valve 46 aof the gas supply pipe 42 a is closed to suspend supply of the HCDS gas.While the APC valve 94 of the exhaust pipe 90 is opened, the inside ofthe process chamber 22 is vacuum-exhausted by the vacuum pump 96, and aresidual gas (an unreacted HCDS gas and/or an HCDS gas that hascontributed to formation of the Si-containing layer) in the processchamber 22 is removed from the inside of the process chamber 22(residual gas removal).

While the valves 56 a, 56 b, 56 c, and 56 d are opened, supply of the N₂gas into the process chamber 22 continues. The N₂ gas serves as a purgegas and an effect of removing the residual gas in the process chamber 22from the inside of the process chamber 22 increases. The HCDS gasadsorbed on the member in the process chamber 22 in step 1 is notcompletely removed by vacuum-exhausting the inside of the processchamber 22, and at least some gas remains while being adsorbed on thesurface of the member in the process chamber 22.

In this case, the residual gas in the process chamber 22 may not becompletely removed and the inside of the process chamber 22 may not becompletely purged. When an amount of the residual gas in the processchamber 22 is small, there is no substantial influence in step 3performed thereafter. There is no need to set a flow rate of the N₂ gassupplied into the process chamber 22 to be high. For example, when thesame amount of the N₂ gas as a volume of the process container [theprocess chamber 22] is supplied, it is possible to purge to the extentthat there is no substantial influence in step 3. When the inside of theprocess chamber 22 is not completely purged in this way (the nextprocess begins at a step at which the gases have been purged to someextent), a purge time decreases, thereby improving the throughput. Also,it is possible to suppress unnecessary consumption of the N₂ gas to theminimum.

Similar to the temperature of the wafer 24 when the HCDS gas issupplied, the temperature of the heater 14 is set to fall within, forexample, a range of 350° C. to 800° C., preferably 450° C. to 800° C.,and more preferably 550° C. to 750° C. The supply flow rate of the N₂gas supplied from each inert gas supply system as a purge gas is set tohave a flow rate of, for example, a range of 100 sccm to 2,000 sccm. Asthe purge gas, instead of the N₂ gas, a rare gas such as Ar, He, Ne, andXe may also be used.

(Step 3)

In step 3, as a reaction gas, the O₂ gas and the H₂ gas are supplied tothe heated wafer 24 in the process chamber 20 under sub-atmosphericpressure. The layer (Si-containing layer) formed in step 1 is oxidizedand modified to an oxide layer.

After the residual gas in the process chamber 22 is removed, the valve46 c of the gas supply pipe 42 c is opened and the O₂ gas flows into thegas supply pipe 42 c. The O₂ gas flows from the gas supply pipe 42 c anda flow rate thereof is adjusted by the MFC 44 c. The O₂ gas having theadjusted flow rate is supplied from the gas supply hole 48 c of thenozzle 40 c into the process chamber 22 in a heated and depressurizedstate.

The valve 46 d of the gas supply pipe 42 d is opened and the H₂ gasflows into the gas supply pipe 42 d. The H₂ gas flows from the gassupply pipe 42 d and a flow rate thereof is adjusted by the MFC 44 d.The H₂ gas having the adjusted flow rate is supplied from the gas supplyhole 48 c of the nozzle 40 c into the process chamber 22 in a heated anddepressurized state through the gas supply pipe 42 c.

When the H₂ gas passes through the gas supply pipe 42 c, the H₂ gas ismixed with the O₂ gas in the gas supply pipe 42 c. The mixed gas of theO₂ gas and the H₂ gas is supplied from the gas supply hole 48 c of thenozzle 40 c to the wafer 24 in the process chamber 22 in a heated anddepressurized state, and then is exhausted from the exhaust pipe 90. Inthis manner, the O₂ gas and the H₂ gas are supplied to the wafer 24 (O₂gas+H₂ gas supply).

At this time, the valve 56 c of the inert gas supply pipe 52 c is openedand the N₂ gas may also be supplied from the inert gas supply pipe 52 c.A flow rate of the N₂ gas is adjusted by the MFC 54 c and the N₂ gas issupplied into the gas supply pipe 42 c. Also, the valve 56 d of theinert gas supply pipe 52 d is opened and the N₂ gas may also be suppliedas an inert gas from the inert gas supply pipe 52 d. A flow rate of theN₂ gas is adjusted by the MFC 54 d and the N₂ gas is supplied into thegas supply pipe 42 c. In this case, a mixed gas of the O₂ gas, the H₂gas and the N₂ gas is supplied from the nozzle 40 c. As the inert gas,instead of the N₂ gas, a rare gas such as Ar, He, Ne, and Xe may also beused.

In order to prevent the O₂ gas and H₂ gas from being introduced into thenozzles 40 a and 40 b, the valves 56 a and 56 b are opened, and the N₂gas flows into the inert gas supply pipes 52 a and 52 b. The N₂ gas issupplied into the process chamber 22 through the gas supply pipe 42 aand the nozzle 40 a, the cleaning gas supply pipe 62 b and the nozzle 40b, and is exhausted from the exhaust pipe 90.

By adjusting the APC valve 94, the pressure in the process chamber 22 ismaintained below atmospheric pressure, for example, in a range of 1 Pato 1,000 Pa. The supply flow rate of the O₂ gas controlled by the MFC 44c is set to have a flow rate of, for example, a range of 1,000 sccm to10,000 sccm. The supply flow rate of the H₂ gas controlled by the MFC 44d is set to have a flow rate of, for example, a range of 1,000 sccm to10,000 sccm. The supply flow rate of the N₂ gas controlled by the MFCs54 a, 54 b, 54 c, and 54 d is set to have a flow rate of, for example, arange of 100 sccm to 2,000 sccm. A time for supplying the O₂ gas and theH₂ gas to the wafer 24, that is, a gas supply time [radiation time] isset to fall within, for example, a range of 1 second to 120 seconds.

Similar to the temperature range of the wafer 24 when the HCDS gas issupplied in step 1, the temperature of the heater 14 is set to have thetemperature range in which oxidizing power is significantly improved(described later), for example, a range of 450° C. to 800° C., andpreferably 550° C. to 750° C. When the temperature falls within thisrange, oxidizing power significantly increases by adding the H₂ gas tothe O₂ gas under a depressurized atmosphere. In addition, when thetemperature of the wafer 24 is excessively low, it is difficult toincrease the oxidizing power.

In consideration of the throughput, it is preferable that thetemperature of the heater 14 be set to maintain the temperature in theprocess chamber 22 from steps 1 to 3 to the same temperature range. Itis preferable that the temperature of the heater 14 be set to maintainthe temperature in the process chamber 22 from steps 1 to 4 to the sametemperature range. In this case, the temperature of the heater 14 is setsuch that the temperature in the process chamber 22 is maintainedconstant to fall within, for example, a range of 450° C. to 800° C., andpreferably 550° C. to 750° C., from steps 1 to 4.

Under the above-described conditions, when the O₂ gas and the H₂ gas aresupplied into the process chamber 22, the O₂ gas and the H₂ gas arethermally activated (excited) as non-plasma and reacted under a heatedand depressurized atmosphere. Thereby, a water (H₂O)-free oxidizingspecies which contains oxygen such as atomic oxygen (O) is generated.Then, the oxidation reaction is mainly performed on the Si-containinglayer formed on the wafer 24 in step 1 by this oxidizing species. Sinceenergy of the oxidizing species is higher than bond energy of Si—N,Si—Cl, Si—H, and Si—C included in the Si-containing layer, when theenergy of the oxidizing species is applied to the Si-containing layer,bonds of Si—N, Si—Cl, Si—H, and Si—C included in the Si-containing layerare disconnected. N, H, Cl, and C, whose bonds with Si are disconnected,are removed from the film and discharged as N₂, H₂, Cl₂, HCl, CO₂, andthe like. Also, when bonds with N, H, Cl, and C are disconnected, theremaining bonds of Si combine with O included in the oxidizing speciesand Si—O bonds are formed. In this way, the Si-containing layer ischanged to a silicon oxide layer (SiO₂ layer, hereinafter referred tosimply as a SiO layer) having low content of impurities such as Cl(modified).

According to the oxidation reaction, it is possible to significantlyincrease the oxidizing power compared to when only the O₂ gas issupplied or water vapor (H₂O) is supplied. Under a depressurizedatmosphere, when the H₂ gas is added with the O₂ gas, it is possible tosignificantly increase the oxidizing power compared to when only the O₂gas is supplied or the H₂O gas is supplied.

The oxidizing species generated in the process chamber 22 is supplied tothe wafer 24 and is also supplied to the surface of the member in theprocess chamber 22. As a result, a part of the Si-containing layerformed on the surface of the member in the process chamber 22 is changedto a SiO layer similar to the Si-containing layer formed on the wafer 24(modified).

In step 3, either or both of the O₂ gas and the H₂ gas may flow by beingactivated as plasma. When the O₂ gas and/or the H₂ gas flow by beingactivated as plasma, the oxidizing species including an active specieshaving higher energy may be generated. When the oxidation reaction isperformed using this oxidizing species, device characteristics may alsoimprove.

In the above-described temperature range, when the O₂ gas and the H₂ gasare activated by heat and sufficiently reacted, an H₂O-free oxidizingspecies such as atomic oxygen (O) is sufficiently generated. Thereby,when the O₂ gas and the H₂ gas are thermally activated as non-plasma, itis possible to obtain sufficient oxidizing power. When the O₂ gas andthe H₂ gas are supplied by being activated by heat, there is no plasmadamage and a relatively soft reaction can be generated. Therefore, it ispossible to perform the above-described oxidation reaction relativelysoftly.

As the oxygen-containing gas, that is, the oxidizing gas, instead of theO₂ gas, ozone (O₃) gas and the like may also be used. In theabove-described temperature range, a test was performed to observe aneffect of adding the hydrogen-containing gas to nitric oxide (NO) gas ornitrous oxide (N₂O) gas. The result showed that an effect of oxidizingpower improvement is not obtained compared to when only the NO gas orthe N₂O gas is supplied. As the oxygen-containing gas, an N-freeoxygen-containing gas (a gas containing O without N) is preferably used.

As the hydrogen-containing gas, that is, the reducing gas, instead ofthe H₂ gas, deuterium (D₂) gas and the like may also be used. Whenammonia (NH₃) gas, methane (CH₄) gas, and the like are used, nitrogen(N) impurities or carbon (C) impurities may be considered to be mixedinto the film. As the hydrogen-containing gas, an other-element-freehydrogen-containing gas (a gas containing hydrogen or deuterium withoutany other elements) is preferably used.

As the oxygen-containing gas, at least one gas selected from the groupconsisting of the O₂ gas and the O₃ gas may be used. As thehydrogen-containing gas, at least one gas selected from the groupconsisting of the H₂ gas and the D₂ gas may be used.

(Step 4)

After the Si-containing layer is changed to the SiO oxide layer, thevalve 46 c of the gas supply pipe 42 c is closed to suspend supply ofthe O₂ gas. Also, the valve 46 d of the gas supply pipe 42 d is closedto suspend supply of the H₂ gas. While the APC valve 94 of the exhaustpipe 90 is opened, the inside of the process chamber 22 isvacuum-exhausted by the vacuum pump 96, and the remaining O₂ gas and H₂gas, the reaction by-products, and the like are removed from the insideof the process chamber 22 (removal of residual gas). While the valves 56a, 56 b, 56 c, and 56 d are opened, supply of the N₂ gas as an inert gasinto the process chamber 22 is maintained. The N₂ gas serves as a purgegas and further increases an effect of removing the unreacted gas or O₂gas that has contributed to formation of the SiO layer, the H₂ gas, thereaction by-products, and the like remaining in the process chamber 22from the inside the process chamber 22.

At this time, the residual gas in the process chamber 22 may not becompletely removed and the inside of the process chamber 22 may not becompletely purged. When an amount of the residual gas in the processchamber 22 is small, there is no substantial influence in step 1performed thereafter. There is no need to set a flow rate of the N₂ gassupplied into the process chamber 22 to be high. For example, when thesame amount of the N₂ gas as a volume of the reaction tube 16 [theprocess chamber 22] is supplied, it is possible to purge to the extentthat there is no substantial influence in step 1. When the inside of theprocess chamber 22 is not completely purged in this way (the nextprocess begins at a step at which the gases are purged to some extent),a purge time decreases, thereby improving the throughput. Also, it ispossible to suppress unnecessary consumption of the N₂ gas to theminimum.

Similar to the temperature of the wafer 24 when the O₂ gas and the H₂gas are supplied, the temperature of the heater 14 is set to fallwithin, for example, a range of 450° C. to 800° C., and preferably 550°C. to 750° C. The supply flow rate of the N₂ gas supplied as a purge gasfrom each inert gas supply system is set to have a flow rate of, forexample, a range of 100 sccm to 2,000 sccm. As the purge gas, instead ofthe N₂ gas, a rare gas such as Ar, He, Ne, and Xe may also be used.

<Performing Predetermined Number of Times>

When a cycle including steps 1 to 4 is performed a predetermined numberof times (n times), a SiO film having a predetermined film thickness isformed on the wafer 24.

<Purging and Restoring to Atmospheric Pressure>

After the SiO film having a predetermined film thickness is formed, thevalves 56 a, 56 b, 56 c, and 56 d are opened, and the N₂ gas is suppliedas an inert gas from each of the inert gas supply pipes 52 a, 52 b, 52c, and 52 d into the process chamber 22 and is exhausted from theexhaust pipe 90. The N₂ gas serves as a purge gas, the inside of theprocess chamber 22 is purged with the inert gas, and the residual gas inthe process chamber 22 is removed from the inside of the process chamber22 (purge). Then, the atmosphere in the process chamber 22 is replacedwith the inert gas, and the pressure in the process chamber 22 isrestored to the normal pressure (restoration to atmospheric pressure).

<Boat Unloading and Wafer Discharge>

The seal cap 100 is lowered by the boat elevator 106, and thereby thelower end of the manifold 18 is opened, and the processed wafer 24 isunloaded (boat unloading) to the outside of the reaction tube 16 fromthe lower end of the manifold 18 while being held on the boat 28. Afterthe boat is unloaded, the shutter 110 moves by the shutter opening andclosing mechanism 112 and the lower-end opening of the manifold 18 issealed by the shutter 110 through the O ring 20 c (shutter closing).Then, the processed wafer 24, that is, the batch-processed wafer 24, isextracted from the boat 28 (wafer discharge).

<Cleaning Process>

Subsequently, cleaning of the inside of the process chamber 22 isperformed. During the process of forming the SiO film, a film is alsodeposited on inner walls of the reaction tube 16 and the manifold 18,the surface of the boat 28, and the like. This deposited film(deposition film) is accumulated and becomes gradually thicker when theabove-described batch process is repeatedly performed. This accumulateddeposition film is released therefrom in a subsequent process and isadhered to the wafer 24, thereby becoming a foreign material. For thisreason, in preparation for the subsequent process, the deposition filmis removed from the inside of the process chamber 22 when the depositionfilm has a predetermined thickness.

(Boat Loading)

The boat 28 [empty boat 28] having no wafer 24 loaded thereon is loadedin the process chamber 22 according to the same sequences as in theabove-described boat loading.

(Pressure Adjustment and Temperature Adjustment)

The inside of the process chamber 22 is vacuum-exhausted to a desiredpressure (degree of vacuum) by the vacuum pump 96. At this time, thepressure in the process chamber 22 is measured by the pressure sensor92, and the APC valve 94 is feedback-controlled based on information onthe measured pressure (pressure adjustment). The vacuum pump 96constantly operates while at least cleaning of the inside of the processchamber 22 is completed.

The inside of the process chamber 22 is heated to a desired temperatureby the heater 14. At this time, based on information on the temperaturedetected by the temperature sensor 114, power supply to the heater 14 isfeedback-controlled (temperature adjustment) such that the inside of theprocess chamber 22 has a desired temperature distribution. Heating theinside of the process chamber 22 by the heater 14 is continuouslypreformed while at least cleaning of the inside of the process chamber22 is completed.

Subsequently, the boat 28 is rotated by the rotating mechanism 102.Rotation of the boat 28 by the rotating mechanism 102 is continuouslyperformed while at least cleaning of the inside of the process chamber22 is completed. Also, the boat 28 may not be rotated.

Cleaning Gas Supply Example 1

Subsequently, a cleaning gas is supplied into the process chamber 22. InExample 1 of a cleaning gas supply pattern, as illustrated in FIG. 7,first, the cleaning gas is supplied from the nozzle 40 c and then thecleaning gas is supplied from the nozzle 40 b.

Since the nozzle 40 c is used to supply the reaction gas for modifyingthe Si-containing layer formed on the wafer 24, it is configured tosupply the gas to the vicinity of the wafer 24 accommodated in theprocess chamber 22. Thereby, the nozzle 40 c is more likely to supplythe gas to the reaction tube 16 side, that is a part (top in FIG. 1) inwhich the wafer 24 in the process chamber 22 is accommodated, than themanifold 18 side. Therefore, when the gas is supplied from the nozzle 40c, the reaction tube 16 side is more likely to be cleaned than themanifold 18 side. On the other hand, the nozzle 40 b is configured tosupply the gas to the manifold 18 side rather than the nozzle 40 c.Thereby, the nozzle 40 b is more likely to supply the gas to themanifold 18 side, for example, the inner wall surface of the manifold18, than the reaction tube 16 side. As a result, when the gas issupplied from the nozzle 40 b, the manifold 18 side is more likely to becleaned than the reaction tube 16 side.

Also, the HCDS gas supplied into the process chamber 22 in step 1 issupplied to the wafer 24 and is also supplied to the surface of themember in the process chamber. In addition, the oxidizing speciesgenerated in the process chamber 22 in step 3 is supplied to the wafer24 and is also supplied to the surface of the member in the processchamber 22. As a result, a part of the Si-containing layer formed on thesurface of the member in the process chamber 22 in step 1 is changed(modified) to the SiO layer similar to the Si-containing layer formed onthe wafer 24 in step 3. However, in step 3, a supply amount of theH₂O-free oxidizing species containing oxygen such as atomic oxygen (O)becomes smaller in the low-temperature region [a region that is notsurrounded by the heater 14 and is a region other than a regionhorizontally surrounding the wafer arrangement region] in the processchamber 22 than the high-temperature region [a region that is surroundedby the heater 14 and is a region horizontally surrounding the waferarrangement region]. In addition, in step 1, the adsorption layer of theHCDS gas is likely to be formed thicker in the low-temperature region ofthe process chamber 22 than the high-temperature region. As a result,the Si-containing layer formed on the low-temperature region isunreacted or partially reacted, and is likely to remain in aninsufficient oxidation state. Specifically, the adsorption layer of theHCDS gas formed on a lower part of the inner wall of the reaction tube16, the inner wall of the manifold 18, lower parts of the nozzles 40 aand 40 c, the top surface of the seal cap 100, a side surface of therotary shaft 104, a side surface or a bottom surface of the insulationmember 30, the inner wall of the exhaust pipe 90, and the like out ofthe members in the process chamber 22 is unreacted or partially reacted,and is likely to remain in an insufficient oxidation state.

In addition, when the boat unloading is performed, outside air[atmosphere] containing H₂O is introduced from the lower-end opening ofthe manifold 18 into the process chamber 22. Thereby, the inner wall ofthe manifold 18, the top surface of the seal cap 100, the side surfaceof the rotary shaft 104, the side surface or the bottom surface of theinsulation member 30, and the like are exposed to the atmospherecontaining H₂O. As described above, the thick adsorption layer of theHCDS gas is formed on the lower part of the inner wall of the reactiontube 16, the inner wall of the manifold 18, the lower parts of thenozzles 40 a and 40 c, the top surface of the seal cap 100, the sidesurface of the rotary shaft 104, the side surface or the bottom surfaceof the insulation member 30, the inner wall of the exhaust pipe 90, andthe like out of the members in the process chamber 22, and remains in aninsufficient oxidation state. When the boat unloading is performed inthis state, the adsorption layer of the HCDS gas may be oxidized by theH₂O in the atmosphere and changed to reaction by-products containing Cl.Also, a film (deposition film) formed by deposition of the reactionby-products is relatively fragile and easily released therefrom, therebyeasily becoming a foreign material (particles).

For this reason, when the cleaning gas is supplied from a side closer tothe manifold 18 toward the low-temperature region, even if thedeposition film, which is relatively fragile and easily releasedtherefrom, is formed on the low-temperature region, this deposition filmis easily cleaned and the deposition film is effectively removed fromthe inside of the process chamber 20.

In this manner, when the cleaning gas is supplied from the nozzle 40 cand the nozzle 40 b, a time required for cleaning the inside of theprocess chamber 22 is reduced compared to when only the nozzle 40 c isused to supply the cleaning gas (Comparative Example 1 in FIG. 7).

In the process of supplying the cleaning gas, specifically, the valve 66a of the cleaning gas supply pipe 62 a is opened and the HF gas flowsinto the cleaning gas supply pipe 62 a. The HF gas flows from thecleaning gas supply pipe 62 a and a flow rate thereof is adjusted by theMFC 64 a. The HF gas having the adjusted flow rate is supplied from thegas supply hole 48 c of the nozzle 40 c into the process chamber 22,comes in contact with the inner walls of the reaction tube 16 and themanifold 18, the surface of the boat 28, and the like, and is exhaustedfrom the exhaust pipe 90. At this time, the valve 56 b of the inert gassupply pipe 52 b is opened and the N₂ gas is supplied as an inert gasfrom the nozzle 40 b. By the HF gas supplied from the nozzle 40 c andthe N₂ gas supplied from the nozzle 40 b, as illustrated in FIG. 8a ,cleaning is mainly performed on a region having a relatively hightemperature such as the inner wall of the reaction tube 16, the surfaceof the boat 28, and the like (high-temperature region cleaning).

Also, at this time, in order to prevent the HF gas from being introducedinto the nozzle 40 a, it is preferable that the valve 56 a be opened andthe N₂ gas flow into the inert gas supply pipe 52 a. In this case, theN₂ gas is supplied into the process chamber 22 through the gas supplypipe 42 a and the nozzle 40 a and is exhausted from the exhaust pipe 90.

After the HF gas is supplied from the nozzle 40 c for a predeterminedtime, the valve 66 a of the cleaning gas supply pipe 62 a and the valve56 b of the inert gas supply pipe 52 b are closed to suspend supply ofthe HF gas from the cleaning gas supply pipe 62 a and supply of the N₂gas from the inert gas supply pipe 52 b. Subsequently, the valve 66 b ofthe cleaning gas supply pipe 62 b is opened and the HF gas flows intothe cleaning gas supply pipe 62 b. The HF gas flows from the cleaninggas supply pipe 62 b and a flow rate thereof is adjusted by the MFC 64b. The HF gas having the adjusted flow rate is supplied from the gassupply hole 48 b of the nozzle 40 b into the process chamber 22, comesin contact with the inner wall of the manifold 18, the top surface ofthe seal cap 100, the side surface of the rotary shaft 104, and thelike, and is exhausted from the exhaust pipe 90. At this time, thevalves 56 c and 56 d of the inert gas supply pipes 52 c and 52 d areopened, and the N₂ gas is supplied as an inert gas from the nozzle 40 c.By the HF gas supplied from the nozzle 40 b and the N₂ gas supplied fromthe nozzle 40 c, as illustrated in FIG. 8b , cleaning is mainlyperformed on a region having a relatively low temperature such as theinner wall of the manifold 18, the top surface of the seal cap 100, theside surface of the rotary shaft 104, and the like (low-temperatureregion cleaning). After the HF gas is supplied from the nozzle 40 b fora predetermined time, the valve 66 b of the cleaning gas supply pipe 62b and the valves 56 c and 56 d of the inert gas supply pipes 52 c and 52d are closed to suspend supply of the HF gas from the cleaning gassupply pipe 62 b and supply of the N₂ gas from the inert gas supplypipes 52 c and 52 d.

Also, at this time, in order to prevent the HF gas from being introducedinto the nozzle 40 a, it is preferable that the valve 56 a be opened andthe N₂ gas flow into the inert gas supply pipe 52 a. In this case, theN₂ gas is supplied into the process chamber 22 through the gas supplypipe 42 a and the nozzle 40 a and is exhausted from the exhaust pipe 90.

When cleaning is performed, the APC valve 94 is adjusted such that thepressure in the process chamber 22 is set to fall within, for example, arange of 133 Pa to 50,000 Pa. The supply flow rate of the HF gascontrolled by the MFCs 64 a and 64 b is set to have a flow rate of, forexample, a range of 1 sccm to 1,000 sccm. The temperature of the heater14 is preferably set such that the temperature of the process chamber 22falls within, for example, a range of 75° C. or more and less than 100°C. When the HF gas is used as the cleaning gas and the temperature isless than 75° C., the HF gas may be adsorbed in multiple layers on thesurfaces of the reaction tube 16, the manifold 18, and the like. Thismultilayer adsorption may cause a corrosion reaction. In addition, whenthe temperature is 100° C. or more, the metal member may be corroded.

Instead of using only the HF gas as the cleaning gas, a gas in which theHF gas is diluted with an inert gas such as N₂ gas, Ar gas, and He gas,a mixed gas of the HF gas and fluorine (F₂) gas, a mixed gas of the HFgas and chlorine fluoride (ClF₃) gas, ClF₃ gas, and the like may also beused.

<Purging and Restoring to Atmospheric Pressure>

After the HF gas is supplied for a predetermined time and the depositionfilm is removed, the valves 56 a, 56 b, 56 c, and 56 d are opened, theN₂ gas is supplied as an inert gas from each of the inert gas supplypipes 52 a, 52 b, 52 c, and 52 d into the process chamber 22, and isexhausted from the exhaust pipe 90. The N₂ gas serves as a purge gas,the inside of the process chamber 22 is purged with the inert gas, andthe residual gas in the process chamber 22 is removed from the inside ofthe process chamber 22 (purge). Then, the atmosphere in the processchamber 22 is replaced with the inert gas, and the pressure in theprocess chamber 22 is restored to the normal pressure (restoration toatmospheric pressure).

<Boat Unloading>

According to the same sequences as in the above-described boatunloading, the boat 28 is unloaded to the outside of the reaction tube16. Then, the lower-end opening of the manifold 18 is sealed by theshutter 110.

Similar to the above-described Example 1, when the high-temperatureregion cleaning and the low-temperature region cleaning arenon-simultaneously performed, that is, asynchronously performed, whilethe inert gas such as the N₂ gas is supplied into the reaction tube 16through the nozzle 40 a when cleaning is performed on thelow-temperature region, the HF gas is preferably supplied to the innerwall surface of the manifold 18 through the nozzle 40 b. At this time,more preferably, the inert gas such as the N₂ gas is supplied into thereaction tube 16 through the nozzle 40 c.

In this way, by the N₂ gas supplied into the reaction tube 16, the HFgas supplied toward the inner wall surface of the manifold 18 throughthe nozzle 40 b may be pushed downward. That is, by the N₂ gas suppliedinto the reaction tube 16, it is possible to suppress (block) the HF gassupplied toward the inner wall surface of the manifold 18 through thenozzle 40 b from flowing and diffusing into an upper part in thereaction tube 16. Thereby, the HF gas supplied through the nozzle 40 bmay aggressively (intensively) come in contact with the low-temperatureregion such as the inner wall surface of the manifold 18, and it ispossible to efficiently remove the deposition that is adhered to thelow-temperature region such as the inner wall surface of the manifold 18and is relatively difficult to remove. It is confirmed that removing thedeposition adhered to the low-temperature region such as the inner wallsurface of the manifold 18 is more difficult than removing thedeposition adhered to the high-temperature region such as the inner wallsurface of the reaction tube 16. According to regulation of flowing anddiffusing of the HF gas by the N₂ gas, it is possible to efficientlyremove the deposition that is adhered to the low-temperature region andis relatively difficult to remove.

In addition, unlike the low-temperature region cleaning, the HF gas ispreferably supplied into the reaction tube 16 through the nozzle 40 cwhile the inert gas such as the N₂ gas is supplied into the manifold 18through the nozzle 40 b when cleaning is performed on thehigh-temperature region. Thereby, the HF gas supplied into the reactiontube 16 is pressured up from the bottom, and it is possible to suppress(block) the HF gas from flowing and diffusing into the manifold 18.Accordingly, it is possible to efficiently remove the deposition adheredto the inner wall of the reaction tube 16.

Also, it is preferable that a supply concentration [a concentration ofthe HF gas in the nozzle 40 b] of the HF gas supplied through the nozzle40 b when cleaning is performed on the low-temperature region be sethigher than a supply concentration [a concentration of the HF gas in thenozzle 40 c] of the HF gas supplied through the nozzle 40 c whencleaning is performed on the high-temperature region. For example, thesupply concentration of the HF gas supplied through the nozzle 40 b isset to 80% to 100%, for example, 100%, and the supply concentration ofthe HF gas supplied through the nozzle 40 c is set to 10% to 30%, forexample, 10% to 20%. Thereby, by the high-concentration HF gas suppliedthrough the nozzle 40 b, it is possible to efficiently remove thedeposition that is adhered to the low-temperature region such as theinner wall surface of the manifold 18 and is relatively difficult toremove. As described above, it is confirmed that removing the depositionadhered to the low-temperature region such as the inner wall surface ofthe manifold 18 is more difficult than removing the deposition adheredto the high-temperature region such as the inner wall surface of thereaction tube 16. By adjusting the concentration of the HF gas, it ispossible to efficiently remove the deposition that is adhered to thelow-temperature region and is relatively difficult to remove. Also, thesupply concentration of the HF gas may be represented by, for example,an equation “supply flow rate of HF gas/(supply flow rate of HFgas+supply flow rate of N₂ gas)”, and each supply concentration of HFgas may be controlled by, for example, adjusting the supply flow rate ofthe HF gas and the supply flow rate of the N₂ gas supplied into eachnozzle. For example, the supply concentration of the HF gas suppliedthrough the nozzle 40 b may be controlled by adjusting the supply flowrate of the HF gas supplied into the cleaning gas supply pipe 62 b andthe supply flow rate of the N₂ gas supplied into the inert gas supplypipe 52 b by the MFCs 64 b and 54 b, respectively. Also, for example,the supply concentration of the HF gas supplied through the nozzle 40 cmay be controlled by adjusting the supply flow rate of the HF gassupplied into the cleaning gas supply pipe 62 a and the supply flow rateof the N₂ gas supplied into the inert gas supply pipes 52 c and 52 d bythe MFCs 64 a, 54 c, and 54 d, respectively.

As a gas supply pattern when the cleaning gas is supplied, the followingExamples 2 to 5 may also be used instead of the above-described Example1.

Cleaning Gas Supply Example 2

In Example 2 of a cleaning gas supply pattern, the cleaning gas issupplied from the nozzle 40 c and the cleaning gas is also supplied fromthe nozzle 40 b.

Specifically, the valve 66 a of the cleaning gas supply pipe 62 a isopened and the HF gas flows into the cleaning gas supply pipe 62 a. TheHF gas flows from the cleaning gas supply pipe 62 a and a flow ratethereof is adjusted by the MFC 64 a. The HF gas having the adjusted flowrate is supplied from the gas supply hole 48 c of the nozzle 40 c intothe process chamber 22, comes in contact with the inner walls of thereaction tube 16 and the manifold 18, the surface of the boat 28, andthe like, and is exhausted from the exhaust pipe 90. Cleaning is mainlyperformed on a region having a relatively high temperature such as theinner wall of the reaction tube 16 and the surface of the boat 28 by theHF gas supplied from the nozzle 40 c.

At the same time, the valve 66 b of the cleaning gas supply pipe 62 b isopened and the HF gas flows into the cleaning gas supply pipe 62 b. TheHF gas flows from the cleaning gas supply pipe 62 b and a flow ratethereof is adjusted by the MFC 64 b. The HF gas having the adjusted flowrate is supplied from the gas supply hole 48 b of the nozzle 40 b intothe process chamber 22, comes in contact with the inner wall of themanifold 18, the top surface of the seal cap 100, the side surface ofthe rotary shaft 104, and the like, and is exhausted from the exhaustpipe 90. Cleaning is mainly performed on a region having a relativelylow temperature such as the inner wall of the manifold 18, the topsurface of the seal cap 100, the side surface of the rotary shaft 104,and the like by the HF gas supplied from the nozzle 40 b. After the HFgas is supplied from the nozzle 40 c and the nozzle 40 b for apredetermined time, the valve 66 a of the cleaning gas supply pipe 62 aand the valve 66 b of the cleaning gas supply pipe 62 b are closed tosuspend supply of the HF gas from the cleaning gas supply pipe 62 a andthe cleaning gas supply pipe 62 b.

Also, at this time, in order to prevent the HF gas from being introducedinto the nozzle 40 a, it is preferable that the valve 56 a be opened andthe N₂ gas flow into the inert gas supply pipe 52 a. In this case, theN₂ gas is supplied into the process chamber 22 through the gas supplypipe 42 a and the nozzle 40 a and is exhausted from the exhaust pipe 90.

According to Example 2, a time required for cleaning is reduced comparedto that of Comparative Example 1 and is further reduced compared to thatof Example 1.

Cleaning Gas Supply Example 3

In Example 3 of a cleaning gas supply pattern, supply of the cleaninggas from the nozzle 40 c and supply of the cleaning gas from the nozzle40 b are alternately performed a plurality of times.

Specifically, the valve 66 a of the cleaning gas supply pipe 62 a isopened and the HF gas flows into the cleaning gas supply pipe 62 a. TheHF gas flows from the cleaning gas supply pipe 62 a and a flow ratethereof is adjusted by the MFC 64 a. The HF gas having the adjusted flowrate is supplied from the gas supply hole 48 c of the nozzle 40 c intothe process chamber 22, comes in contact with the inner walls of thereaction tube 16 and the manifold 18, the surface of the boat 28, andthe like, and is exhausted from the exhaust pipe 90. At this time, thevalve 56 b of the inert gas supply pipe 52 b is opened and the N₂ gas issupplied as an inert gas from the nozzle 40 b. By the HF gas suppliedfrom the nozzle 40 c and the N₂ gas supplied from the nozzle 40 b, asillustrated in FIG. 8a , cleaning is mainly performed on a region havinga relatively high temperature such as the inner wall of the reactiontube 16, the surface of the boat 28, and the like (high-temperatureregion cleaning).

Also, at this time, in order to prevent the HF gas from being introducedinto the nozzle 40 a, it is preferable that the valve 56 a be opened andthe N₂ gas flow into the inert gas supply pipe 52 a. In this case, theN₂ gas is supplied into the process chamber 22 through the gas supplypipe 42 a and the nozzle 40 a and is exhausted from the exhaust pipe 90.

After the HF gas is supplied from the nozzle 40 c for a predeterminedtime (a time shorter than that of Example 1), the valve 66 a of thecleaning gas supply pipe 62 a and the valve 56 b of the inert gas supplypipe 52 b are closed to suspend supply of the HF gas from the cleaninggas supply pipe 62 a and supply of the N₂ gas from the inert gas supplypipe 52 b. Subsequently, the valve 66 b of the cleaning gas supply pipe62 b is opened and the HF gas flows into the cleaning gas supply pipe 62b. The HF gas flows from the cleaning gas supply pipe 62 b and a flowrate thereof is adjusted by the MFC 64 b. The HF gas having the adjustedflow rate is supplied from the gas supply hole 48 b of the nozzle 40 binto the process chamber 22, comes in contact with the inner wall of themanifold 18, the top surface of the seal cap 100, the side surface ofthe rotary shaft 104, and the like, and is exhausted from the exhaustpipe 90. At this time, the valves 56 c and 56 d of the inert gas supplypipes 52 c and 52 d are opened, and the N₂ gas is supplied as an inertgas from the nozzle 40 c. By the HF gas supplied from the nozzle 40 band the N₂ gas supplied from the nozzle 40 c, as illustrated in FIG. 8b, cleaning is mainly performed on a region having a relatively lowtemperature such as the inner wall of the manifold 18, the top surfaceof the seal cap 100, the side surface of the rotary shaft 104, and thelike (low-temperature region cleaning). After the HF gas is suppliedfrom the nozzle 40 b for a predetermined time (a time shorter than thatof Example 1), the valve 66 b of the cleaning gas supply pipe 62 b andthe valves 56 c and 56 d of the inert gas supply pipes 52 c and 52 d areclosed to suspend supply of the HF gas from the cleaning gas supply pipe62 b and supply of the N₂ gas from the inert gas supply pipes 52 c and52 d.

Also, at this time, in order to prevent the HF gas from being introducedinto the nozzle 40 a, it is preferable that the valve 56 a be opened andthe N₂ gas flow into the inert gas supply pipe 52 a. In this case, theN₂ gas is supplied into the process chamber 22 through the gas supplypipe 42 a and the nozzle 40 a and is exhausted from the exhaust pipe 90.

Supply of the HF gas from the nozzle 40 c and supply of the N₂ gas fromthe nozzle 40 b, and supply of the HF gas from the nozzle 40 b andsupply of the N₂ gas from the nozzle 40 c are alternately performed aplurality of times. That is, the high-temperature region cleaning andthe low-temperature region cleaning are alternately repeatedlyperformed.

According to Example 3, a time required for cleaning is reduced comparedto that of Comparative Example 1 as much as in Example 1. Also, when thehigh-temperature region cleaning and the low-temperature region cleaningis set as one cycle, according to the number of times the cycle isperformed, it is possible to control a removal amount (etching amount)of the deposition respectively adhered to the high-temperature regionand the low-temperature region

Cleaning Gas Supply Example 4

In Example 4 of a cleaning gas supply pattern, while the cleaning gas iscontinuously supplied from the nozzle 40 b, the cleaning gas isintermittently supplied from the nozzle 40 c.

Specifically, the valve 66 b of the cleaning gas supply pipe 62 b isopened and the HF gas flows into the cleaning gas supply pipe 62 b. TheHF gas flows from the cleaning gas supply pipe 62 b and a flow ratethereof is adjusted by the MFC 64 b. The HF gas having the adjusted flowrate 22 is supplied from the gas supply hole 48 b of the nozzle 40 binto the process chamber 22, comes in contact with the inner wall of themanifold 18, the top surface of the seal cap 100, the side surface ofthe rotary shaft 104, and the like, and is exhausted from the exhaustpipe 90. Cleaning is mainly performed on a region having a relativelylow temperature such as the inner wall of the manifold 18, the topsurface of the seal cap 100, the side surface of the rotary shaft 104,and the like by the HF gas supplied from the nozzle 40 b.

To this end, the valve 66 a of the cleaning gas supply pipe 62 a isopened and the HF gas flows into the cleaning gas supply pipe 62 a. TheHF gas flows from the cleaning gas supply pipe 62 a and a flow ratethereof is adjusted by the MFC 64 a. The HF gas having the adjusted flowrate is supplied from the gas supply hole 48 c of the nozzle 40 c intothe process chamber 22, comes in contact with the inner walls of thereaction tube 16 and the manifold 18, the surface of the boat 28, andthe like, and is exhausted from the exhaust pipe 90. Cleaning is mainlyperformed on a region having a relatively high temperature such as theinner wall of the reaction tube 16, the surface of the boat 28, and thelike by the HF gas supplied from the nozzle 40 c. After the HF gas issupplied from the nozzle 40 c for a predetermined time (a time shorterthan that of Example 1), the valve 66 a of the cleaning gas supply pipe62 a is closed to suspend supply of the HF gas from the cleaning gassupply pipe 62 a. Subsequently, after a predetermined time [for example,a time for which the valve 66 a is opened] passes, the valve 66 a of thecleaning gas supply pipe 62 a is opened again, and the HF gas flows intothe cleaning gas supply pipe 62 a. By repeating this manipulation, theHF gas is intermittently supplied from the nozzle 40 c.

According to Example 4, a time required for cleaning is reduced comparedto that of Comparative Example 1 and is further reduced compared to thatof Example 1. Also, since a time for contacting the HF gas with theregion having a relatively low temperature may be set to be greater thana time for contacting the HF gas with the region having a relativelyhigh temperature, it is possible to intensively perform cleaning on theregion having a relatively low temperature.

Cleaning Gas Supply Example 5

In Example 5 of a cleaning gas supply pattern, while the cleaning gas iscontinuously supplied from the nozzle 40 c, the cleaning gas isintermittently supplied from the nozzle 40 b.

Specifically, the valve 66 a of the cleaning gas supply pipe 62 a isopened and the HF gas flows into the cleaning gas supply pipe 62 a. TheHF gas flows from the cleaning gas supply pipe 62 a and a flow ratethereof is adjusted by the MFC 64 a. The HF gas having the adjusted flowrate is supplied from the gas supply hole 48 c of the nozzle 40 c intothe process chamber 22, comes in contact with the inner walls of thereaction tube 16 and the manifold 18, the surface of the boat 28, andthe like, and is exhausted from the exhaust pipe 90. Cleaning is mainlyperformed on a region having a relatively high temperature such as theinner wall of the reaction tube 16 and the surface of the boat 28 by theHF gas supplied from the nozzle 40 c.

To this end, the valve 66 b of the cleaning gas supply pipe 62 b isopened and the HF gas flows into the cleaning gas supply pipe 62 b. TheHF gas flows from the cleaning gas supply pipe 62 b and a flow ratethereof is adjusted by the MFC 64 b. The HF gas having the adjusted flowrate 22 is supplied from the gas supply hole 48 b of the nozzle 40 binto the process chamber 22, comes in contact with the inner wall of themanifold 18, the top surface of the seal cap 100, the side surface ofthe rotary shaft 104, and the like, and is exhausted from the exhaustpipe 90. Cleaning is mainly performed on a region having a relativelylow temperature such as the inner wall of the manifold 18, the topsurface of the seal cap 100, the side surface of the rotary shaft 104,and the like by the HF gas supplied from the nozzle 40 b. After the HFgas is supplied from the nozzle 40 b for a predetermined time (a timeshorter than that of Example 1), the valve 66 b of the cleaning gassupply pipe 62 b is closed to suspend supply of the HF gas from thecleaning gas supply pipe 62 b. Subsequently, after a predetermined time[for example, a time for which the valve 66 b is opened] passes, thevalve 66 b of the cleaning gas supply pipe 62 b is opened again, and theHF gas flows into the cleaning gas supply pipe 62 b. By repeating thismanipulation, the HF gas is intermittently supplied from the nozzle 40b.

According to Example 5, a time required for cleaning is reduced comparedto that of Comparative Example 1, is further reduced compared to that ofExample 1, and is equally reduced as in Example 4.

Second Embodiment

Next, the second embodiment will be described. In the first embodiment,the L-shaped nozzle 40 b including the gas supply hole 48 b openedupward is connected to the cleaning gas supply pipe 62 b. In the secondembodiment, the nozzle 320 b is connected to the cleaning gas supplypipe 62 b. This is a difference between the two embodiments. In thepresent embodiment, the same numerals are assigned to substantially thesame components as those in the first embodiment and descriptionsthereof will not be repeated.

As illustrated in FIG. 9, the nozzle 320 b has an I shape [short pipeshape], and a main body portion is provided to penetrate a sidewall ofthe manifold 18 such that a leading end thereof is substantially flushwith the inner wall of the manifold 18. Also, the leading end of thenozzle 320 b may be projected from the inner wall of the manifold 18.

A gas supply hole 322 b configured to supply a gas is provided in theleading end of the nozzle 320 b. The gas supply hole 322 b is configuredto be opened [opened to a direction from the inner wall side of themanifold 18 to the inner side] toward a side (horizontal direction). Thenozzle 320 b is configured to supply a gas to the inner side in theprocess chamber 20 from the manifold 18 side relative to a position inwhich the nozzle 40 a supplies a gas. In addition, the nozzle 320 b isable to supply a gas to the inner wall surface of the manifold 18.

Third Embodiment

Next, the third embodiment will be described. In the first embodiment,the nozzle 40 b including the gas supply hole 48 b opened upward isconnected to the cleaning gas supply pipe 62 b. In the third embodiment,a nozzle 330 b is connected to the cleaning gas supply pipe 62 b. Thisis a difference between the two embodiments. In the present embodiment,the same numerals are assigned to substantially the same components asthose in the first embodiment and descriptions thereof will not berepeated.

As illustrated in FIG. 10, the nozzle 330 b is an L-shaped short nozzle,and is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsupward along an inner wall of the manifold 18.

A gas supply hole 332 b is provided in the sidewall of the manifold 18side of the vertical portion of the nozzle 330 b, and the gas supplyhole 332 b is configured to be opened toward the inner wall surface ofthe manifold 18. That is, the gas supply hole 332 b is provided so as toface (oppose) the inner wall surface of the manifold 18. The nozzle 330b is configured to directly supply a gas from the manifold 18 side tothe inner wall side of the manifold 18 relative to a position in whichthe nozzle 40 a supplies a gas.

Fourth Embodiment

Next, the fourth embodiment will be described. In the first embodiment,the nozzle 40 b including the gas supply hole 48 b opened upward isconnected to the cleaning gas supply pipe 62 b. In the fourthembodiment, a nozzle 340 b is connected to the cleaning gas supply pipe62 b. This is a difference between the two embodiments. In the presentembodiment, the same numerals are assigned to substantially the samecomponents as those in the first embodiment and descriptions thereofwill not be repeated.

As illustrated in FIG. 11, the nozzle 340 b is an L-shaped short nozzle,and is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsupward along an inner wall of the manifold 18.

A gas supply hole 342 b configured to supply a gas is provided in aleading end of the nozzle 340 b, and the gas supply hole 342 b is openedupward [opened in a direction from the manifold 18 side to the reactiontube 16 side]. Also, a gas supply hole 344 b is provided in a sidewallof the manifold 18 side of the vertical portion of the nozzle 340 b. Thegas supply hole 344 b is configured to be opened toward the inner wallsurface of the manifold 18. The nozzle 340 b is configured to supply agas to the upper part in the process chamber 20 and the inner wall sideof the manifold 18 from the manifold 18 side relative to a position inwhich the nozzle 40 a supplies a gas. The nozzle 340 b is able todirectly supply a gas toward the inner wall surface of the manifold 18.

Fifth Embodiment

Next, the fifth embodiment will be described. In the first embodiment,the nozzle 40 b including the gas supply hole 48 b opened upward isconnected to the cleaning gas supply pipe 62 b. In the fifth embodiment,a nozzle 350 b is connected to the cleaning gas supply pipe 62 b. Thisis a difference between the two embodiments. In the present embodiment,the same numerals are assigned to substantially the same components asthose in the first embodiment and descriptions thereof will not berepeated.

As illustrated in FIG. 12, the nozzle 350 b is an L-shaped short nozzle,and is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsdownward along an inner wall of the manifold 18.

A gas supply hole 352 b configured to supply a gas is provided in aleading end of the nozzle 350 b, and the gas supply hole 352 b is openeddownward [opened in a direction from the manifold 18 side to the sealcap 100 side]. That is, the gas supply hole 352 b is provided so as toface (oppose) the seal cap 100. The nozzle 350 b is configured to supplya gas to the lower part in the process chamber 20 from the manifold 18side relative to a position in which the nozzle 40 a supplies a gas. Thenozzle 350 b is able to directly supply a gas toward the top surface ofthe seal cap 100.

Sixth Embodiment

Next, the sixth embodiment will be described. In the first embodiment,the nozzle 40 b including the gas supply hole 48 b opened upward isconnected to the cleaning gas supply pipe 62 b. In the sixth embodiment,a nozzle 360 b is connected to the cleaning gas supply pipe 62 b. Thisis a difference between the two embodiments. In the present embodiment,the same numerals are assigned to substantially the same components asthose in the first embodiment and descriptions thereof will not berepeated.

As illustrated in FIG. 13, the nozzle 360 b is an L-shaped short nozzle,and is provided such that a horizontal portion thereof penetrates asidewall of the manifold 18 and a vertical portion thereof extendsdownward along an inner wall of the manifold 18.

A gas supply hole 362 b configured to supply a gas is provided in aleading end of the nozzle 360 b, and the gas supply hole 362 b is openeddownward [opened in a direction from the manifold 18 side to the sealcap 100 side]. That is, the gas supply hole 362 b is provided so as toface (oppose) the seal cap 100. Also, a gas supply hole 364 b isprovided in a sidewall of the manifold 18 side of the vertical portionof the nozzle 360 b. The gas supply hole 364 b is configured to beopened toward the inner wall surface of the manifold 18. That is, thegas supply hole 364 b is provided so as to face (oppose) the manifold18. The nozzle 360 b is configured to supply a gas to the lower part inthe process chamber 20 and the inner wall side of the manifold 18 fromthe manifold 18 side relative to a position in which the nozzle 40 asupplies a gas. The nozzle 360 b is able to directly supply a gas towardthe top surface of the seal cap 100 and the inner wall surface of themanifold.

Seventh Embodiment

Next, the seventh embodiment will be described. In the seventhembodiment, a cover 400 covering the inner wall surface is provided inthe inner wall surface of the manifold 18 side of the first embodiment.As illustrated in FIG. 14, the cover 400 is provided on the top surfaceof the seal cap 100, and made of, for example, a heat-resistant material(nonmetallic material) such as quartz and SiC. The gas supply hole 48 bof the nozzle 40 b is disposed in a gap between the cover 400 and themanifold 18, and the HF gas flows between the cover 400 and the manifold18.

It is preferable that the cover 400 be provided concentrically with themanifold 18 in the inner side of the manifold 18. That is, it ispreferable that the cover 400 be provided to cover the entire inner wallsurface of the manifold 18 so as to face (oppose) the inner wall surfaceof the manifold 18. In such a configuration, since the HF gas comes incontact with the inner wall surface of the manifold 18 more aggressively(intensively), it is possible to efficiently remove the deposition thatis adhered to the inner wall surface of the manifold 18 and isrelatively difficult to remove. The cover 400 serves as a guide portion,which allows the HF gas to aggressively flow along the inner wallsurface of the manifold 18, that is, a gas flow regulating portion (gasflow regulating unit).

Eighth Embodiment

Next, the eighth embodiment will be described. In the eighth embodiment,similar to the seventh embodiment, a cover 410 covering the inner wallsurface is provided in the inner wall side of the manifold 18 of thefirst embodiment. As illustrated in FIG. 15, the cover 410 includes atop surface portion 410 a and a side surface portion 410 b. The topsurface portion 410 a is configured to horizontally extend from an upperend of the side surface portion 410 b to the outside [the manifold 18side]. The top surface portion 410 a is also called an extendingportion. Since the side surface portion 410 b vertically extends [issuspended] from an end of the top surface portion 410 a to a lower part,it is also called a suspended portion. A protrusion 18 a horizontallyprojecting toward the inner side of the manifold 18 is provided in anupper end of the inner wall of the manifold 18. The top surface portion410 a of the cover 410 is supported by the protrusion 18 a. Theprotrusion 18 a serves as a support portion supporting the cover 410.The cover 410 is provided such that a lower part thereof is opened, andis made of, for example, a heat-resistant material (nonmetallicmaterial) such as quartz and SiC. The gas supply hole 48 b of the nozzle40 b is disposed in a gap between the cover 410 and the manifold 18, andthe HF gas flows between the cover 410 and the manifold 18.

It is preferable that the cover 410 be provided concentrically with themanifold 18 in the inner side of the manifold 18. That is, it ispreferable that the cover 410 be provided to cover substantially theentire inner wall surface of the manifold 18 so as to face (oppose) theinner wall surface of the manifold 18. In such a configuration, sincethe HF gas comes in contact with the inner wall surface of the manifold18 more aggressively (intensively), it is possible to efficiently removethe deposition that is adhered to the inner wall surface of the manifold18 and is relatively difficult to remove. The cover 410 serves as aguide portion, which allows the HF gas to aggressively flow along theinner wall surface of the manifold 18, that is, a gas flow regulatingportion (gas flow regulating unit).

Even in such a configuration, since the HF gas comes in contact with theinner wall surface of the manifold 18 more aggressively (intensively),it is possible to efficiently remove the deposition that is adhered tothe inner wall surface of the manifold 18 and is relatively difficult toremove.

Also, the top surface portion 410 a of the cover 410 may be providedbetween the reaction tube 16 and the manifold 18. In this case, sincethere is no need to provide the protrusion 18 a in the manifold 18, itis possible to simplify a shape of the manifold 18, thereby reducing aprocessing cost of the manifold 18, that is, a manufacturing cost of thesubstrate processing apparatus. In addition, the top surface of thecover 410 may be opened by providing an opening such as a slit and ahole in the top surface portion 410 a of the cover 410 and the topsurface of the cover 410. Also, an upper part may be opened by reversingthe cover 410 upside down.

Also, the covers 400 and 410 and each nozzle of the first to sixthembodiments may be appropriately combined.

In the above-described first to eighth embodiments, while a case inwhich the substrate processing apparatus 10 having no plasma source hasbeen described, the present invention is not limited thereto but theplasma source may be used. However, when the plasma source is notincluded, it is possible to simplify a structure of the substrateprocessing apparatus compared to when the plasma source is included.Therefore, it is possible to reduce a manufacturing cost of thesubstrate processing apparatus.

In the above embodiment, the HF gas is not supplied from the nozzle 40a. While deposition having SiO as a main component is adhered to themember in the process chamber 20 in the process of forming the SiO film,deposition having Si as a main component is adhered to the inside of thenozzle 40 a, that is, the inner wall of the nozzle 40 a, since only HCDSgas flows into the nozzle 40 a. However, it is difficult to remove thedeposition having Si as a main component using the HF gas. Therefore, inthe cleaning process, even when the HF gas flows into the nozzle 40 a,it is difficult to remove the deposition having Si as a main componentadhered to the inner wall of the nozzle 40 a.

Also, when the HF gas flows into the nozzle 40 a, the HF gas may beintroduced into a gap between the deposition having Si as a maincomponent adhered to the inner wall of the nozzle 40 a and the innerwall of the nozzle 40 a. Thereby, an interface between the inner wall ofthe nozzle 40 a and the deposition having Si as a main component maybecome unstable. When the process of forming the SiO film is performedin this state, the deposition having Si as a main component adhered tothe inner wall of the nozzle 40 a is partially released therefrom duringthe film-forming, and thereby a foreign material may be generated andadhered to the wafer 24.

Therefore, in the present embodiment, the HF gas is not supplied intothe reaction tube 16 through the nozzle 40 a in the cleaning process andthe HF gas is supplied into the reaction tube 16 through the nozzle 40c. That is, supply of the HF gas into the reaction tube 16 through thenozzle 40 a is not performed.

When the HF gas is supplied into the reaction tube 16 through the nozzle40 c, in order to prevent the HF gas from being introduced into thenozzle 40 a, it is preferable that an inert gas such as the N₂ gas besupplied into the nozzle 40 a. That is, it is preferable that the valve56 a of the inert gas supply pipe 52 a be opened and the N₂ gas as aninert gas be supplied from the inert gas supply pipe 52 a. Thereby, itis possible to prevent the foreign material from being generated due toan unstable interface between the inner wall of the nozzle 40 a and thedeposition having Si as a main component.

Also, there is no need to clean the inside of the nozzle 40 a, that is,to remove the deposition having Si as a main component adhered to theinner wall of the nozzle 40 a. The nozzle 40 a may be exchanged when anaccumulated film has a predetermined thickness of, for example, 4 μm to5 μm, that is a thickness before the foreign material is generated aftera release occurs in the deposition.

Also, in the present embodiment, even when the HF gas is supplied towardthe inner wall surface of the manifold 18 through the nozzle 40 b, theHF gas may not be supplied into the reaction tube 16 through the nozzle40 a.

Even when the HF gas is supplied toward the inner wall surface of themanifold 18 through the nozzle 40 b, in order to prevent the HF gas frombeing introduced into the nozzle 40 a, it is preferable that an inertgas such as the N₂ gas be supplied into the nozzle 40 a. Thereby, it ispossible to prevent the foreign material from being generated due to anunstable interface between the inner wall of the nozzle 40 a and thedeposition having Si as a main component. At this time, it is preferablethat the HF gas be prevented from being introduced into the nozzle 40 cby supplying the inert gas such as the N₂ gas into the nozzle 40 c.

In addition, in the process of forming the SiO film, since only the O₂gas or the H₂ gas flows into the nozzle 40 c, no deposition is adheredto the inside of the nozzle 40 c, that is, the inner wall of the nozzle40 c, or even when the deposition is adhered thereto, it is caused by asmall amount of the HCDS gas introduced into the nozzle 40 c, andthereby only a small amount of the deposition is adhered thereto. As aresult, there is no need to clean the inside of the nozzle 40 c.

Also, in the above embodiment, while a configuration in which the O₂ gasand the H₂ gas are supplied through the same nozzle [the nozzle 40 c]into the process chamber 22 has been described, the present invention isnot limited thereto and each gas may also be supplied into the processchamber 22 from a separate nozzle. However, when a plurality of types ofgases use a common nozzle, it is advantageous in that the number ofnozzles decreases, a device cost decreases, and maintenance becomeseasier, compared to when separate nozzles are provided. The nozzle forsupplying the HCDS gas and the nozzle for supplying the H₂ gas may sharea nozzle and the gases may be supplied through the same nozzle. This isbecause, under the above-described processing conditions, when the H₂gas and the HCDS gas adhered to the inside of the nozzle come incontact, there is no film-forming reaction. In addition, it ispreferable that the nozzle for supplying the HCDS gas and the nozzle forsupplying the O₂ gas be separately provided. This is because, accordingto temperature conditions, when the O₂ gas and the HCDS gas adhered tothe inside of the nozzle come in contact, the film-forming reaction isgenerated and the thick deposition may be formed.

In the above embodiment, while the example in which thechlorosilane-based source gas is used as a source gas when theSi-containing layer is formed in step 1 has been described, instead ofthe chlorosilane-based source gas, a fluorosilane-based material gas ora silane-based material gas having a halogen-based ligand other than achloro group may also be used.

The fluorosilane-based material gas refers to a fluorosilane-basedmaterial in a gas state, for example, a gas obtained by vaporizing afluorosilane-based material that is in a liquid state under normaltemperature and normal pressure, or a fluorosilane-based material thatis in a gas state under normal temperature and normal pressure. Inaddition, the fluorosilane-based material refers to a silane-basedmaterial having a fluoro group as a halogen group, and a sourceincluding at least silicon (Si) and fluorine (F). That is, thefluorosilane-based material may also be a kind of halide.

As the fluorosilane-based material gas, a silicon fluoride gas such astetrafluorosilane [silicon tetrafluoride (SiF₄)] gas andhexafluorodisilane (Si₂F₆) gas may be used. In this case, when theSi-containing layer is formed, the fluorosilane-based material gas issupplied to the wafer 24 in the process chamber 22. The Si-containinglayer formed in this way includes either or both of the adsorption layerof the fluorosilane-based material gas and the Si layer.

In the above embodiment, while the example in which, in step 3 of theprocess of forming the SiO film, the O₂ gas and the H₂ gas are suppliedinto the process chamber 22 that is heated under sub-atmosphericpressure, and the Si-containing layer is changed to the SiO layer hasbeen described, the present invention is not limited thereto. In step 3,the H₂ gas is not supplied and only the oxygen-containing gas such as O₂gas, O₃ gas, and H₂O gas may be supplied. In addition, theseoxygen-containing gases may also be supplied by being activated asplasma.

In the above embodiment, while the example in which the HCDS gas, the O₂gas and the H₂ gas are alternately supplied into the process chamber 22to from the SiO film on the wafer 24 has been described, the presentinvention is not limited thereto. Alternatively, the HCDS gas and theoxygen-containing gas such as the O₂ gas, the O₃ gas, and the H₂O gasmay be simultaneously supplied into the process chamber 22 to form theSiO film on the wafer 24.

In the above embodiment, while the example in which the silicon-basedthin film including silicon, that is a semiconductor element, is formedas a thin film, has been described, the present invention is not limitedthereto. The present invention may also be preferably applied when ametal-based thin film containing a metal element such as titanium (Ti),zirconium (Zr), hafnium (Hf), tantalum (Ta), aluminum (Al), andmolybdenum (Mo) is formed as a thin film.

As a metal-based thin film containing Ti, when a titanium oxide film(TiO film) is formed, as a source gas, for example, a gas which containsTi and a chloro group such as titanium tetrachloride (TiCl₄) or a gaswhich contains Ti and a fluoro group such as titanium tetrafluoride(TiF₄) may be used. As an oxygen-containing gas and ahydrogen-containing gas, the same gases as in the above-describedembodiment may be used. Processing conditions may be the same, forexample, as in the above-described embodiment.

As a metal-based thin film containing Zr, when a zirconium oxide film(ZrO film) is formed, as a source gas, for example, a gas which containsZr and a chloro group such as zirconium tetrachloride (ZrCl₄) or a gaswhich contains Zr and a fluoro group such as zirconium tetrafluoride(ZrF₄) may be used. As an oxygen-containing gas and ahydrogen-containing gas, the same gases as in the above-describedembodiment may be used. Processing conditions may be the same, forexample, as in the above-described embodiment.

As a metal-based thin film containing Hf, when a hafnium oxide film (HfOfilm) is formed, as a source gas, for example, a gas which contains Hfand a chloro group such as hafnium tetrachloride (HfCl₄) or a gas whichcontains Hf and a fluoro group such as hafnium tetrafluoride (HfF₄) maybe used. As an oxygen-containing gas and a hydrogen-containing gas, thesame gases as in the above-described embodiment may be used. Processingconditions may be the same, for example, as in the above-describedembodiment.

As a metal-based thin film containing Ta, when a tantalum oxide film(TaO film) is formed, as a source gas, for example, a gas which containsTa and a chloro group such as tantalum pentachloride (TaCl₅) or a gaswhich contains Ta and a fluoro group such as tantalum pentafluoride(TaF₅) may be used. As an oxygen-containing gas and ahydrogen-containing gas, the same gases as in the above-describedembodiment may be used. Processing conditions may be the same, forexample, as in the above-described embodiment.

As a metal-based thin film containing Al, when an aluminum oxide film(AlO film) is formed, as a source gas, for example, a gas which containsAl and a chloro group such as aluminum trichloride (AlCl₃) or a gaswhich contains Al and a fluoro group such as aluminum trifluoride (AlF₃)may be used. As an oxygen-containing gas and a hydrogen-containing gas,the same gases as in the above-described embodiment may be used.Processing conditions may be the same, for example, as in theabove-described embodiment.

As a metal-based thin film containing Mo, when a molybdenum oxide film(MoO film) is formed, as a source gas, for example, a gas which containsMo and a chloro group such as molybdenum pentachloride (MoCl₅) or a gaswhich contains Mo and a fluoro group such as molybdenum pentafluoride(MoF₅) may be used. As an oxygen-containing gas and ahydrogen-containing gas, the same gases as in the above-describedembodiment may be used. Processing conditions may be the same, forexample, as in the above-described embodiment.

In this way, the present invention is applied to form the silicon-basedthin film and is also applied to form the metal-based thin film. In thiscase, the same action effects as in the above-described embodiment maybe obtained. That is, the present invention may be preferably appliedwhen a thin film including a predetermined element such as asemiconductor element and a metal element is formed.

In the above embodiment, while the case in which, in the cleaningprocess, after the boat is loaded, the cleaning gas is supplied into theprocess chamber 20 [cleaning the inside of the process chamber 20 isperformed while the boat 28 is accommodated in the process chamber 20]has been described, the present invention is not limited thereto. Whencleaning of the boat 28 is unnecessary, the boat loading may be skipped[while the boat 28 is not accommodated in the process chamber 20] andthe cleaning gas may also be supplied into the process chamber 20.

In the above embodiment, while the example in which a thin film isformed using the batch-type substrate processing apparatus thatprocesses a plurality of substrates at once has been described, thepresent invention is not limited thereto but may also be preferablyapplied when a thin film is formed using a single wafer type substrateprocessing apparatus that processes a single substrate or severalsubstrates at once.

In the above embodiment, while the example in which the substrateprocessing apparatus including a hot wall-type processing furnace isused to form a thin film has been described, the present invention isnot limited thereto but may also be preferably applied to when asubstrate processing apparatus including a cold wall-type processingfurnace is used to form a thin film.

The first to eighth embodiments, each of Examples, and the like may beappropriately combined and used.

In any of the first to eighth embodiments, when Example 2 of a cleaninggas supply pattern is applied, in any embodiment, the process ofsupplying the cleaning gas into the reaction tube 16 and the process ofsupplying the cleaning gas toward the inner wall surface of the manifold18 are simultaneously performed. In particular, in the third, fourth,and sixth to eighth embodiments, when Example 2 of a cleaning gas supplypattern is applied, the process of supplying the cleaning gas into thereaction tube 16 and the process of directly supplying the cleaning gastoward the inner wall surface of the manifold 18 or the top surface ofthe seal cap 100 are simultaneously performed.

In any of the third, fourth, and sixth to eighth embodiments, whenExample 3 of a cleaning gas supply pattern is applied, the process ofsupplying the cleaning gas into the reaction tube 16 and the process ofdirectly supplying the cleaning gas toward the inner wall surface of themanifold 18 or the top surface of the seal cap 100 are alternatelyrepeatedly performed.

In any of the third, fourth, and sixth to eighth embodiments, when anyof Examples 3 to 5 of a cleaning gas supply pattern is applied, at leastone of the process of supplying the cleaning gas into the reaction tube16 and the process of directly supplying the cleaning gas toward theinner wall surface of the manifold 18 or the top surface of the seal cap100 is intermittently performed.

In any of the third, fourth, and sixth to eighth embodiments, whenExample 4 or 5 of a cleaning gas supply pattern is applied, either theprocess of supplying the cleaning gas into the reaction tube 16 or theprocess of directly supplying the cleaning gas toward the inner wallsurface of the manifold 18 or the top surface of the seal cap 100 isintermittently performed, and the other process is continuouslyperformed.

The present invention may also be implemented by changing, for example,a process recipe or a cleaning recipe of a predetermined substrateprocessing apparatus. When the process recipe or the cleaning recipe ischanged, the process recipe or the cleaning recipe according to thepresent invention is installed in the predetermined substrate processingapparatus through telecommunication lines or a recording medium storingthe process recipe or the cleaning recipe, or the process recipe or thecleaning recipe is directly changed to a process recipe or a cleaningrecipe according to the present invention by manipulating an input andoutput device of the predetermined substrate processing apparatus.

According to the present invention, it is possible to reduce a timerequired for cleaning

Preferred Embodiments of the Present Invention

Hereinafter, preferred embodiments of the present invention are added.

(Supplementary Note 1)

According to an embodiment of the present invention, there is provided acleaning method, including:

(a) providing a process chamber after forming an oxide film on asubstrate in the process chamber formed by a reaction tube and amanifold supporting the reaction tube by performing a cycle apredetermined number of times, the cycle including supplying a sourcegas to the substrate in the process chamber through a first nozzledisposed in the manifold and extending upward from the manifold to aninside of the reaction tube, and supplying an oxidizing gas to thesubstrate in the process chamber through a second nozzle disposed in themanifold and extending upward from the manifold to the inside of thereaction tube; and

(b) cleaning an inside of the process chamber,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

(Supplementary Note 2)

In the cleaning method of Supplementary note 1, it is preferable thatthe first cleaning process and the second cleaning process are performedwithout supplying the hydrogen fluoride gas into the reaction tubethrough the first nozzle. That is, in the first cleaning process, thehydrogen fluoride gas is not supplied into the reaction tube through thefirst nozzle and the hydrogen fluoride gas is supplied into the reactiontube through the second nozzle. In the second cleaning process, thehydrogen fluoride gas is not supplied into the reaction tube through thefirst nozzle and the hydrogen fluoride gas is supplied toward the innerwall surface of the manifold through the third nozzle.

(Supplementary Note 3)

In the cleaning method of Supplementary note 1 or 2, it is preferablethat the first cleaning process and the second cleaning process areperformed with an inert gas being supplied into the reaction tubethrough the first nozzle.

(Supplementary Note 4)

In the cleaning method of any of Supplementary notes 1 to 3, it ispreferable that a concentration of the hydrogen fluoride gas suppliedthrough the third nozzle in the second cleaning process (a concentrationof the hydrogen fluoride gas in the third nozzle) is higher than that ofthe hydrogen fluoride gas supplied through the second nozzle in thefirst cleaning process (a concentration of the hydrogen fluoride gas inthe second nozzle).

(Supplementary Note 5)

In the cleaning method of any of Supplementary notes 1 to 4, it ispreferable that the first cleaning process and the second cleaningprocess are non-simultaneously performed (asynchronously performed).

(Supplementary Note 6)

In the cleaning method of any of Supplementary notes 1 to 5, it ispreferable that the first cleaning process and the second cleaningprocess are alternately performed.

(Supplementary Note 7)

In the cleaning method of any of Supplementary notes 1 to 8, it ispreferable that the first cleaning process and the second cleaningprocess are alternately repeated.

(Supplementary note 8)

In the cleaning method of any of Supplementary notes 5 to 7, it ispreferable that the second cleaning process is performed with an inertgas being supplied into the reaction tube through the second nozzle.

(Supplementary Note 9)

In the cleaning method of any of Supplementary notes 5 to 8, it ispreferable that the second cleaning process is performed with an inertgas being supplied into the reaction tube through the first nozzle andthe second nozzle.

(Supplementary Note 10)

In the cleaning method of Supplementary note 8 or 9, it is preferablethat the hydrogen fluoride gas supplied onto the inner wall surface ofthe manifold through the third nozzle is pushed downward by the inertgas supplied into the reaction tube in the second cleaning process.

(Supplementary Note 11)

In the cleaning method of any of Supplementary notes 8 to 9, it ispreferable that the hydrogen fluoride gas supplied onto the inner wallsurface of the manifold through the third nozzle is prevented (blocked)from flowing and diffusing into an upper portion in the reaction tube(an upper portion within the reaction tube) by the inert gas suppliedinto the reaction tube in the second cleaning process.

(Supplementary Note 12)

In the cleaning method of any of Supplementary notes 1 to 4, it ispreferable that the first cleaning process and the second cleaningprocess are simultaneously performed.

(Supplementary Note 13)

In the cleaning method of any of Supplementary notes 1 to 12, it ispreferable that at least one of the first cleaning process and thesecond cleaning process is intermittently performed.

(Supplementary Note 14)

In the cleaning method of any of Supplementary notes 1 to 13, it ispreferable that a reducing gas is further supplied to the substrate inthe process chamber under sub-atmospheric pressure through the firstnozzle when supplying the oxidizing gas in the cycle.

(Supplementary Note 15)

In the cleaning method of any of Supplementary notes 1 to 14, it ispreferable that a layer is formed on the substrate in the processchamber by supplying the source gas to the substrate in the processchamber through the first nozzle when supplying the source gas in thecycle, and

the layer is oxidized and modified to an oxide layer by supplying theoxidizing gas to the substrate in the process chamber through the secondnozzle and supplying a reducing gas through the first nozzle undersub-atmospheric pressure when supplying the oxidizing gas in the cycle.

(Supplementary Note 16)

According to another embodiment of the present invention, there areprovided a method of manufacturing a semiconductor device, including:

(a) forming an oxide film on a substrate in the process chamber formedby a reaction tube and a manifold supporting the reaction tube byperforming a cycle a predetermined number of times, the cycle includingsupplying a source gas to the substrate in the process chamber through afirst nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube, and supplying an oxidizinggas to the substrate in the process chamber through a second nozzledisposed in the manifold and extending upward from the manifold to theinside of the reaction tube; and

(b) cleaning an inside of the process chamber after the step (a) isperformed,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

(Supplementary Note 17)

According to still another embodiment of the present invention, there isprovided a substrate processing apparatus, including:

a process chamber formed by a reaction tube and a manifold supportingthe reaction tube;

a source gas supply system configured to supply a source gas into theprocess chamber;

an oxidizing gas supply system configured to supply an oxidizing gasinto the process chamber;

a hydrogen fluoride gas supply system configured to supply a hydrogenfluoride gas into the process chamber;

a first nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube;

a second nozzle disposed in the manifold and extending upward from themanifold to the inside of the reaction tube;

a third nozzle disposed in the manifold; and

a control unit configured to control the source gas supply system, theoxidizing gas supply system and the hydrogen fluoride gas supply systemto perform: (a) forming an oxide film on a substrate in the processchamber by performing a cycle a predetermined number of times, the cycleincluding supplying the source gas to the substrate in the processchamber through the first nozzle and supplying the oxidizing gas to thesubstrate in the process chamber through the second nozzle; and (b)cleaning an inside of the process chamber after performing the step (a),wherein the step (b) includes a first cleaning process of supplying thehydrogen fluoride gas into the reaction tube through the second nozzleand a second cleaning process of supplying the hydrogen fluoride gasonto an inner wall surface of the manifold through the third nozzle.

(Supplementary Note 18)

According to yet another embodiment of the present invention, there areprovided a program and a non-transitory computer-readable recordingmedium storing the program causing a computer to execute:

(a) forming an oxide film on a substrate in the process chamber formedby a reaction tube and a manifold supporting the reaction tube byperforming a cycle a predetermined number of times, the cycle includingsupplying a source gas to the substrate in the process chamber through afirst nozzle disposed in the manifold and extending upward from themanifold to an inside of the reaction tube, and supplying an oxidizinggas to the substrate in the process chamber through a second nozzledisposed in the manifold and extending upward from the manifold to theinside of the reaction tube; and

(b) cleaning an inside of the process chamber after the step (a) isperformed,

wherein the step (b) includes:

a first cleaning process of supplying a hydrogen fluoride gas into thereaction tube through the second nozzle; and

a second cleaning process of supplying a hydrogen fluoride gas onto aninner wall surface of the manifold through a third nozzle disposed inthe manifold.

What is claimed is:
 1. A cleaning method, comprising: (a) providing aprocess chamber after forming an oxide film on a substrate in theprocess chamber formed by a reaction tube and a manifold supporting thereaction tube by performing a cycle a predetermined number of times, thecycle including supplying a source gas to the substrate in the processchamber through a first nozzle disposed in the manifold and extendingupward from the manifold to an inside of the reaction tube, andsupplying an oxidizing gas to the substrate in the process chamberthrough a second nozzle disposed in the manifold and extending upwardfrom the manifold to the inside of the reaction tube; and (b) cleaningan inside of the process chamber, wherein the step (b) includes: a firstcleaning process of supplying a hydrogen fluoride gas into the reactiontube through the second nozzle; a second cleaning process of supplying ahydrogen fluoride gas into a gap between the manifold and a guideportion facing an inner wall surface of the manifold and onto the innerwall surface of the manifold through a third nozzle disposed in the gap,and the step (b) is performed with a lower-end opening of the manifoldclosed by a seal cap, and the guide portion is disposed on the seal cap.2. The cleaning method according to claim 1, wherein the first cleaningprocess and the second cleaning process are performed without supplyingthe hydrogen fluoride gas into the reaction tube through the firstnozzle.
 3. The cleaning method according to claim 1, wherein the firstcleaning process and the second cleaning process are performed with aninert gas being supplied into the reaction tube through the firstnozzle.
 4. The cleaning method according to claim 1, wherein aconcentration of the hydrogen fluoride gas supplied through the thirdnozzle in the second cleaning process is higher than that of thehydrogen fluoride gas supplied through the second nozzle in the firstcleaning process.
 5. The cleaning method according to claim 1, whereinthe first cleaning process and the second cleaning process areasynchronously performed.
 6. The cleaning method according to claim 1,wherein the first cleaning process and the second cleaning process arealternately performed.
 7. The cleaning method according to claim 1,wherein the first cleaning process and the second cleaning process arealternately repeated.
 8. The cleaning method according to claim 1,wherein the first cleaning process and the second cleaning process aresimultaneously performed.
 9. The cleaning method according to claim 1,wherein at least one of the first cleaning process and the secondcleaning process is intermittently performed.
 10. The cleaning methodaccording to claim 1, wherein a reducing gas is further supplied to thesubstrate in the process chamber under sub-atmospheric pressure throughthe first nozzle when supplying the oxidizing gas in the cycle.
 11. Thecleaning method according to claim 1, wherein a layer is formed on thesubstrate in the process chamber by supplying the source gas to thesubstrate in the process chamber through the first nozzle when supplyingthe source gas in the cycle, and the layer is oxidized and modified toan oxide layer by supplying the oxidizing gas through the second nozzleand supplying a reducing gas through the first nozzle to the substratein the process chamber under sub-atmospheric pressure when supplying theoxidizing gas in the cycle.
 12. The cleaning method according to claim1, wherein a gas supply hole of the third nozzle is disposed at aposition lower than an upper end of the guide portion.
 13. The cleaningmethod according to claim 1, wherein the guide portion is disposedconcentrically with the inner wall surface of the manifold.
 14. Thecleaning method according to claim 5, wherein the second cleaningprocess is performed with an inert gas being supplied into the reactiontube through the second nozzle.
 15. The cleaning method according toclaim 5, wherein the second cleaning process is performed with an inertgas being supplied into the reaction tube through the first nozzle andthe second nozzle.
 16. The cleaning method according to claim 14,wherein the hydrogen fluoride gas supplied into the gap and onto theinner wall surface of the manifold through the third nozzle is pusheddownward toward a bottom of the manifold by the inert gas supplied intothe reaction tube in the second cleaning process.
 17. The cleaningmethod according to claim 14, wherein the hydrogen fluoride gas suppliedinto the gap and onto the inner wall surface of the manifold through thethird nozzle is prevented from flowing and diffusing into an upperportion in the reaction tube by the inert gas supplied into the reactiontube in the second cleaning process.